JP6084797B2 - Surface light source device and display device - Google Patents

Description

  The present invention relates to a surface light source device having a laser light source and a display device having the surface light source device.

  Conventionally, a surface light source device that irradiates the back surface of a liquid crystal display panel after converting laser light from a laser light source into a planar parallel light beam by a light beam control member as an illumination means for a liquid crystal display monitor used in a personal computer or a television. Is known (see, for example, Patent Document 1).

  Patent Document 1 discloses a surface light source device including a laser light source, a collimator lens that collimates laser light emitted from the laser light source, and a light flux control member that controls light distribution of the laser light transmitted through the collimator lens. Have been described.

  FIG. 1 is a diagram illustrating a configuration of a surface light source device disclosed in Patent Document 1. In FIG. As shown in FIG. 1A (plan view) and FIG. 1B (side view), the light flux controlling member 40 includes an incident surface 41 on which the laser light L emitted from the laser light source 20 is incident, and a laser incident from the incident surface 41. The first prism row 42 that reflects the light L, the second prism row 43 that reflects the laser light L reflected by the first prism row 42, and the emission surface 44 that emits the laser light L reflected by the second prism row 43. And having.

  The first prism row 42 has a plurality of first prisms 45, and the plurality of first prisms 45 is a curve C1 in which a line connecting the vertices when viewed in plan is a quadratic or higher order polynomial. Are arranged as follows. The second prism array 43 includes a plurality of second prisms 46, and the plurality of second prisms 46 has a curve C2 in which a line connecting the vertices when viewed from the front is represented by a second-order or higher polynomial expression. It is arranged to become.

  The laser light L emitted from the laser light source 20 passes through the collimator lens 30 and then enters the light flux controlling member 40 (see FIG. 1A). The laser beam L incident from the incident surface 41 is reflected by the first prism 45 and thereby spread linearly (see FIG. 1A). The laser light L spread in a linear shape is reflected by the second prism 46, and then spread out in a planar shape and then emitted from the emission surface 44 (see FIG. 1B).

International Publication No. 2009/011122

  In the light flux controlling member 40 of the surface light source device 10 of Patent Document 1, the prisms 45 and 46 are arranged so that the lines connecting the vertices of the prisms 45 and 46 become curves C1 and C2 expressed by a second-order or higher polynomial expression. Has been placed. For this reason, in order to reflect the laser beam L at a desired angle, it is necessary to individually optimize the shapes of the prisms 45 and 46 according to the respective positions. Therefore, the surface light source device 10 of Patent Document 1 has a problem that the design and manufacturing process of the light flux controlling member 40 is complicated.

  This invention is made | formed in view of this point, and it is a surface light source device which has a laser light source, Comprising: It aims at providing the surface light source device which can be designed and manufactured easily. Another object of the present invention is to provide a display device having the surface light source device.

  A surface light source device of the present invention is a surface light source device having a light source that emits collimated light having polarization characteristics and a light beam control member that controls an optical path of the collimated light, and the light beam control member is emitted from the light source. A deflecting surface that deflects collimated light, a first prism row that internally reflects and reflects linearly the collimated light deflected by the deflecting surface, and collimated light that is reflected by the first prism row A first prism array including a second prism array that is internally incident and reflected in a planar shape, and an exit surface that emits collimated light reflected by the second prism array, wherein each ridge line is parallel to each other, And a plurality of first prisms arranged so as to be located on the same first virtual plane, and the second prism row is located on the same second virtual plane, with each ridge line being parallel to each other. Arranged as A plurality of second prisms are ridgeline and the ridgeline of the second prism of the first prism has a configuration perpendicular to each other.

  The surface light source device of the present invention is a surface light source device having a light source that emits collimated light having polarization characteristics and a light flux control member that controls the optical path of the collimated light, and the light flux control member is emitted from the light source. A deflecting surface that deflects the collimated light that has been deflected, a first ridge row that causes the collimated light deflected by the deflecting surface to be incident linearly and reflected linearly, and collimated light that is reflected by the first ridge row Are projected in a plane and reflected in a plane, and the first ridges are arranged such that the ridge lines are parallel to each other and located on the same first virtual plane. The plurality of first protrusions are arranged, and the second protrusion row has a plurality of second protrusions arranged such that the ridge lines are parallel to each other and located on the same second virtual plane. The ridge line of the first ridge and the ridge line of the second ridge are perpendicular to each other. .

  The display device of the present invention employs a configuration having the surface light source device of the present invention and a display member that is irradiated with light emitted from the surface light source device.

  According to the present invention, it is possible to provide a surface light source device that can be easily designed and manufactured and a display device having the surface light source device.

1A and 1B are diagrams showing a configuration of a conventional surface light source device. It is a figure which shows the structure of the surface light source device of Embodiment 1. FIG. 2 is a perspective view of a light flux controlling member according to Embodiment 1. FIG. 4A and 4B are partially enlarged plan views of the light flux controlling member of the first embodiment. 5A and 5B are partially enlarged front views of the light flux controlling member of the first embodiment. 6A and 6B are diagrams for explaining the dihedral angle. 6 is a perspective view of a light flux controlling member according to Embodiment 2. FIG. 6 is a perspective view of a light flux controlling member according to Embodiment 3. FIG. FIG. 10 is a perspective view of a light flux controlling member of a modification example of the third embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, a surface light source device suitable for a backlight of a liquid crystal display device will be described as a representative example of the surface light source device of the present invention. In the following description, a surface light source device that uses laser light as collimated light having polarization characteristics will be described. These surface light source devices can be used as a display device by combining with a display member such as a liquid crystal panel.

(Embodiment 1)
In the first embodiment, a description will be given of a light flux controlling member 300 that has a substantially triangular shape when viewed from the front and makes laser light incident from the front side (lateral side).

[Configuration of surface light source device and light flux controlling member]
FIG. 2 is a diagram showing a configuration of the surface light source device 100 according to the first embodiment. As shown in FIG. 2, the surface light source device 100 includes a laser light source 200 and a light flux control member 300.

  The laser light source 200 emits laser light L, which is a small-diameter parallel light beam, toward the front surface (deflection surface 320) of the light beam control member 300. The laser light L emitted from the laser light source 200 enters the light flux controlling member 300 from the front (deflection surface 320).

  3 to 5 are diagrams showing the configuration of the light flux controlling member 300. FIG. FIG. 3 is a perspective view of the light flux controlling member 300. 4A is a partially enlarged plan view of the vicinity of the deflection surface 320 of the light flux controlling member 300, and FIG. 4B is an optical path diagram in the region shown in FIG. 4A. 5A is a partially enlarged front view of the vicinity of the second prism row 360 of the light flux controlling member 300 of Embodiment 1, and FIG. 5B is an optical path diagram in the region shown in FIG. 5A.

  FIG. 6 is a diagram for explaining the dihedral angle. FIG. 6A is a diagram for explaining a dihedral angle when two surfaces are in contact with each other, and FIG. 6B is a diagram for explaining a dihedral angle when two surfaces are separated from each other. .

  As shown in FIG. 3, the light flux controlling member 300 includes a deflection surface 320, a first prism row 340 having a plurality of first prisms 341, a second prism row 360 having a plurality of second prisms 361, and an exit. A surface 380. The plurality of first prisms 341 are arranged such that the first ridge lines 344 are parallel to each other and located on the first virtual plane 345. The plurality of second prisms 361 are arranged such that the second ridge lines 364 are parallel to each other and located on the second virtual plane 365. In the display device described above, the display member is disposed so as to face the emission surface 380.

  The light flux controlling member 300 is formed by integral molding and controls the light distribution of the laser light L emitted from the laser light source 200. The material of the light flux controlling member 300 is not particularly limited as long as it is a material that can transmit light having a desired wavelength. For example, the material of the light flux controlling member 300 is a light transmissive resin such as polymethyl methacrylate (PMMA), polycarbonate (PC), epoxy resin (EP), or glass. As a material for the light flux controlling member 300, a zero / zero birefringent polymer (non-birefringent optical resin, for example, a polymer described in Japanese Patent No. 4624845) having particularly small orientation birefringence and photoelastic birefringence is particularly preferable.

  The light flux controlling member 300 is a substantially flat member. The light beam control member 300 has a substantially rectangular shape in plan view (xy plan view), and the light beam control member 300 has a substantially triangular shape in front view (xz plan view). The deflection surface 320 is disposed on the front surface, the first prism row 340 is disposed on the left side surface, the second prism row 360 is disposed on the bottom surface, and the output surface 380 is disposed on the surface.

  The deflecting surface 320 has a planar shape, and makes the laser light L emitted from the laser light source 200 enter the light flux controlling member 300 and refract it toward the first prism row 340. That is, in the light flux controlling member 300 of the first embodiment, the deflecting surface 320 is an incident surface and also a refracting surface. The deflection surface 320 is disposed on the first prism row 340 side when the light flux controlling member 300 is viewed from the front.

  The dihedral angle between the deflection surface 320 and the exit surface 380 is 90 °. That is, the deflection surface 320 and the exit surface 380 are orthogonal to each other. As shown in FIG. 6A, the “dihedral angle” in the case where the plane A and the plane B are adjacent to each other means that the plane perpendicular to the plane A and the plane B is the plane C, and the intersection of the plane A and the plane C Is the intersection line LA, and the intersection line of the plane B and the plane C is the intersection line LB, it means the smaller angle θ of the two angles formed by the intersection line LA and the intersection line LB. Assuming that the plane A is the deflection surface 320 and the plane B is the exit surface 380, the intersection line LA and the intersection line LB are finite straight lines. One of the two angles formed by the two finite lines in contact at the end is 180 ° or more, and the other is less than 180 °. Therefore, as described above, the “dihedral angle” is less than 180 °.

  Further, as shown in FIG. 4A, the dihedral angle θ1 between the deflection surface 320 and the first virtual plane 345 is an acute angle. As shown in FIG. 6B, the “dihedral angle” when the plane A and the plane B are separated from each other means that the plane perpendicular to the plane A and the plane B is the plane C, and the intersection of the plane A and the plane C When a straight line extending LA is a straight line LA ′ and a straight line extending the intersection line LB of the plane B and the plane C is a straight line LB ′, the smaller of the two angles formed by the straight line LA ′ and the straight line LB ′ Means the angle θ. Assuming that the plane A is the deflection surface 320 and the plane B is the first virtual plane 345, the intersection line LA and the intersection line LB formed by intersecting each plane with the plane C (point P, FIG. 6B). To see). The extended straight lines (straight line LA ′ and straight line LB ′) are finite straight lines that contact at the end (point P). One of the two angles formed by the two finite lines in contact at the end is 180 ° or more, and the other is less than 180 °. Therefore, as described above, the “dihedral angle” is less than 180 °.

  The dihedral angle θ1 between the deflection surface 320 and the first virtual plane 345 is not particularly limited as long as the laser light L can be refracted toward the first prism row 340. The dihedral angle θ1 may be appropriately adjusted according to the traveling direction of the laser light L incident on the light flux controlling member 300, the width dimension of the laser light L, the length of the first prism row 340, and the like.

  As shown in FIG. 4B, the first prism row 340 causes the laser light L deflected by the deflecting surface 320 to be linearly incident inside and reflected linearly toward the second prism row 360. The first prism row 340 includes a plurality of first prisms 341 having the same shape. Each first prism 341 has a triangular prism shape. The cross-sectional shape of the first prism 341 when viewed in plan (xy plane) is a triangle. The first prism 341 includes a first reflecting surface 342 and a first inclined surface 343 that are adjacent to each other via the first ridge line 344. The plurality of first prisms 341 are arranged such that the first ridge lines 344 are parallel to each other and located on the same first virtual plane 345.

  Here, “linearly incident internally” means that when the first prism row 340 is viewed from the deflecting surface 320, the laser light L that has reached the first prism row 340 (first reflecting surface 342) appears to be linear. Means that. In addition, “linearly reflected” means a surface to be irradiated when a virtual surface to be irradiated (surface parallel to the first virtual plane 345) intersecting with each laser beam L reflected by each first reflection surface 342 is considered. This means that the laser beam L irradiated to the lens looks substantially linear.

  The first reflecting surface 342 is disposed on the back side when viewed from the deflecting surface 320, and reflects the laser light L incident from the deflecting surface 320 toward the second prism row 360. The first reflecting surfaces 342 are arranged so as to be parallel to each other. Most of the first reflecting surfaces 342 overlap each other when viewed from the incident position of the deflecting surface 320 on which the laser beam L is incident. The total width dimension of the first reflecting surface 342 seen from the incident position of the deflecting surface 320 on which the laser beam L is incident is the same as the width dimension of the deflected laser beam L, or the width of the deflected laser beam L More than the dimension.

  The first inclined surface 343 is disposed on the near side as viewed from the deflection surface 320 and connects the first reflecting surface 342 of the first prism 341 adjacent to the first reflecting surface 342 of the first prism 341.

  The dihedral angle between the first reflecting surface 342 and the first inclined surface 343 is not particularly limited as long as the deflected laser light L can be reflected in a desired direction. The dihedral angle between the first reflecting surface 342 and the first inclined surface 343 may be adjusted as appropriate according to the positional relationship between the first prism row 341 and the second prism row 361.

  As shown in FIG. 4B, the laser light L deflected by the deflecting surface 320 travels toward the first prism row 340 while maintaining the directivity. Then, the laser light L that has reached the first prism row 340 is linearly incident on the first valley surface 346 side portion of each first reflecting surface 342 in a linear manner. The light linearly incident on each first reflecting surface 342 is reflected linearly toward the second prism row 360.

  The second prism row 360 causes the laser light L reflected by the first prism row 340 to be incident on the surface in a plane shape and reflected in a plane shape toward the emission surface 380. The second prism row 360 includes a plurality of second prisms 361 having the same shape. Each second prism 361 has a triangular prism shape. The cross-sectional shape of the second prism 361 when viewed from the front (xz plane) is a triangle. The second prism 361 has a second reflecting surface 362 and a second inclined surface 363 that are adjacent to each other via the second ridge line 364. The plurality of second prisms 361 are arranged such that the second ridge lines 364 are parallel to each other and located on the same second virtual plane 365. The ridge line of the first prism 341 (first ridge line 344) and the ridge line of the second prism 361 (second ridge line 364) are perpendicular to each other.

  Here, “inner incidence in a planar shape” means that the laser light L that has reached the second prism row 360 (second reflecting surface 362) when the second prism row 360 is viewed from the first prism row 340 is in a planar shape. Means it looks like Further, “reflecting in a planar shape” means that when a virtual irradiated surface (a surface parallel to the second virtual plane 365) intersecting with each laser beam L reflected by each second reflecting surface 362 is considered, the laser beam L Means that a part of the illuminated surface is illuminated substantially uniformly.

  In the display device, each laser beam L reflected by each second reflecting surface 362 is incident on a display member such as a liquid crystal panel. At this time, since the plurality of laser beams L are incident on the display region, the display member is illuminated substantially uniformly.

  As shown in FIG. 5A, the thicknesses of the second virtual plane 365 and the exit surface 380 gradually decrease as the distance from the first virtual plane 345 increases. That is, the dihedral angle θ2 between the second virtual plane 365 and the exit surface 380 is an acute angle. At this time, the dihedral angle between the first virtual plane 345 and the second virtual plane 365 is also an acute angle.

  The second reflecting surface 362 is disposed on the back side when viewed from the first prism row 340, and reflects the laser light L reflected by the first prism row 340 toward the emission surface 380. The second reflecting surfaces 362 are arranged so as to be parallel to each other. When viewed from the reflection position of the first prism row 340 where the laser light L is reflected, most of the respective second reflection surfaces 362 overlap continuously. The total width dimension of the second reflecting surface 362 seen from the reflection position of the first prism row 340 where the laser light L is reflected is the same as or reflected from the total width dimension of the reflected linear laser light L. The total width dimension of the linear laser beam L is greater than or equal to. Further, the total height dimension of the second reflecting surface 362 seen from the reflection position of the first prism row 340 where the laser light L is reflected is the same as or reflected from the height of the reflected linear laser light L. More than the height of the linear laser beam L.

  The second inclined surface 363 is disposed on the near side when viewed from the first prism row 340, and connects the second reflecting surface 362 of the second prism 361 adjacent to the second reflecting surface 362 of the second prism 361.

  The dihedral angle between the second reflecting surface 362 and the second inclined surface 363 is not particularly limited as long as the deflected laser light L can be reflected in a desired direction. The dihedral angle between the second reflecting surface 362 and the second inclined surface 363 may be appropriately adjusted according to the direction in which the laser light L is emitted.

  As shown in FIG. 5B, the laser light L reflected linearly by the first prism row 340 is incident on the second reflecting surface 362 on the second valley line 366 side portion in a planar shape. The light that is internally incident on each second reflecting surface 362 in a planar shape is reflected in a planar shape toward the emitting surface 380.

  The emission surface 380 has a planar shape and emits the planar laser beam L reflected by the second prism row 360.

[effect]
As described above, in the surface light source device 100 of the present invention, the plurality of first prisms 341 can be formed in the same shape, and the plurality of second prisms 361 can be formed in the same shape. Can be designed and manufactured. In addition, since there is no configuration that irregularly scatters the laser light L in the optical path of the laser light L that enters the light flux controlling member 300, the polarized light of the laser light L before the incident is emitted from the surface light source device 100. State is maintained. Furthermore, by configuring the light flux controlling member 300 with a non-birefringent optical resin such as a zero / zero birefringent polymer, a change in polarization state due to the influence of birefringence can be suppressed.

  When the surface light source device 100 of the present invention is applied to a liquid crystal display, a liquid crystal display with high light utilization efficiency is obtained by adjusting the viewing angle using a lenticular sheet or a diffusion sheet after passing through the liquid crystal panel. It becomes possible.

(Embodiment 2)
In the second embodiment, a light beam control member 400 that has a substantially rectangular shape when viewed from the front and makes laser light incident from the front side (lateral side) will be described.

  The surface light source device according to the second embodiment of the present invention differs from the surface light source device 100 according to the first embodiment in that the light source control member 400 according to the second embodiment is provided instead of the light beam control member 300 according to the first embodiment. . Therefore, in the present embodiment, only the light flux controlling member 400 of the second embodiment will be described. The light flux controlling member 400 of the second embodiment is different from the light flux controlling member 300 of the first embodiment only in the form of the first prism row 440 and the second prism row 460. Therefore, the same components as those of the light flux controlling member 300 of Embodiment 1 are denoted by the same reference numerals, and the description thereof is omitted.

[Configuration of luminous flux control member]
FIG. 7 is a perspective view of the light flux controlling member 400 of the second embodiment. As shown in FIG. 7, the light flux controlling member 400 has a deflection surface 320, a first prism row 440, a second prism row 460, and an exit surface 380. The light flux controlling member 400 is a substantially flat member. The light beam control member 400 has a substantially rectangular shape in plan view (xy plan view), and the light beam control member 400 has a substantially rectangular shape in front view (xz plan view).

  The first prism row 440 includes a plurality of first prisms 341 having the same shape. The plurality of first prisms 341 are arranged such that the first ridge lines 344 are parallel to each other and are located on the first virtual plane 345. The dihedral angle between the first virtual plane 345 and the exit surface 380 is an obtuse angle.

  The second prism row 460 includes a plurality of second prisms 361 having the same shape. The plurality of second prisms 361 are arranged such that the second ridge lines 364 are parallel to each other and located on the second virtual plane 365. The ridge line of the first prism 341 (first ridge line 344) and the ridge line of the second prism 361 (second ridge line 364) are perpendicular to each other. The second virtual plane 365 and the exit surface 380 are parallel. The dihedral angle between the first virtual plane 345 and the second virtual plane 365 is an acute angle.

  The laser light L emitted from the laser light source 200 travels in the light beam control member 400 toward the first prism row 440 via the deflection surface 320. Then, the light is internally incident linearly on the first prism row 340 and is reflected linearly toward the second prism row 361. The laser light L incident on the second prism array 460 in a plane is reflected in a plane toward the emission surface 380 and is emitted from the emission surface 380.

[effect]
In addition to the effects of light flux controlling member 300 of Embodiment 1, light flux controlling member 400 of the present invention is excellent in productivity because emission surface 380 and second virtual plane 460 are parallel.

  In the first and second embodiments, an example in which the deflection surface 320 formed in a plane is a plane is shown, but the deflection surface 320 may not be a plane. For example, an achromatic diffraction grating may be formed on the deflecting surface 320. When collimated light of three colors of RGB (red, green, and blue) (for example, laser light) is incident on a deflecting surface 320 constituted by a plane, color separation occurs because the refractive index differs for each wavelength. This color separation can be suppressed by forming an achromatic diffraction grating on the deflecting surface 320.

(Embodiment 3)
In the third embodiment, a description will be given of a light flux controlling member 500 that has a substantially triangular shape when viewed from the front and makes laser light incident from the bottom side (lower side).

  The surface light source device according to the third embodiment of the present invention has an emission position of the laser light source 200 and a light beam control member 500 according to the third embodiment instead of the light beam control member 300 according to the first embodiment. 1 different from the surface light source device 100 of FIG. The light flux controlling member 500 of the third embodiment is different from the light flux controlling member 300 of the first embodiment only in the form of the deflection surface 320. Therefore, the same components as those of the light flux controlling member 300 of Embodiment 1 are denoted by the same reference numerals, and the description thereof is omitted.

[Configuration of luminous flux control member]
FIG. 8 is a diagram illustrating a configuration of the light flux controlling member 500 according to the third embodiment. As shown in FIG. 8, the laser light source 200 emits laser light L from the bottom surface side (lower side) of the light flux controlling member 500. The laser light L emitted from the laser light source 200 is incident on the light flux controlling member 500 from the bottom surface side (lower side).

  As shown in FIG. 8, light flux controlling member 500 has incident surface 590 in addition to deflecting surface 520, first prism row 340, second prism row 360, and exit surface 360. The light flux controlling member 500 is a substantially flat member. The light beam control member 500 has a substantially rectangular shape in plan view (xy plan view), and the light beam control member 500 has a substantially triangular shape in front view (xz plan view).

  The incident surface 590 causes the laser beam L emitted upward from the laser light source 200 to enter the light flux controlling member 500. The incident surface 590 is disposed on the bottom surface side of the light flux controlling member 500 and is disposed in parallel with the exit surface 380.

  The deflecting surface 520 has a planar shape and reflects the laser light L incident from the incident surface 590 toward the first prism row 340. That is, in light flux controlling member 500 of Embodiment 3, deflection surface 520 is a reflecting surface. The dihedral angle between the deflection surface 520 and the exit surface 380 is an obtuse angle. The dihedral angle between the deflection surface 520 and the first virtual plane 345 is an acute angle.

  Laser light L emitted from the laser light source 200 enters the light flux controlling member 500 from the incident surface 590 and travels toward the deflecting surface 520. Then, the laser light L that has entered the light flux controlling member 520 is reflected by the deflecting surface 520 and travels toward the first prism row 340. Then, the light is internally incident linearly on the first prism row 340 (first reflection surface 342) and reflected linearly toward the second prism row 360. The laser light L incident on the second prism array 360 in a plane is reflected in a plane toward the emission surface 380 and is emitted from the emission surface 380.

[effect]
As described above, the light beam control member 500 of the present invention can arrange the laser light source 200 on the lower side in addition to the effects of the light beam control member 300 of the first embodiment. Therefore, in the case of a display device using a plurality of surface light source devices of the present invention, the surface light source devices can be arranged densely and the display member can be efficiently irradiated.

[Modification]
As shown in FIG. 9, the light flux controlling member 500 ′ may further have a reflecting surface 595. In this case, the laser light source 200 is disposed below the light flux controlling member 500 ′ and emits the laser light L in the lateral direction. Further, the light flux controlling member 500 ′ reflects the laser light L incident from the incident surface 590 ′ by the reflecting surface 595 and makes it incident on the deflecting surface 520. In the light flux controlling member 500 ′ of the modified example, the laser light source 200 can be disposed on the lower side of the light flux controlling member 500 ′ and emitted in the lateral direction, so that the entire apparatus can be made thin.

  Also in the light beam control member 400 of the second embodiment, instead of the deflection surface 320, the incident surface 590 and the deflection surface 520 of the light beam control members 500 and 500 ′ of the third embodiment, or the incident surface 590 ′, and the reflection surface. 595 and the deflection surface 520 may be formed.

  In each of the above-described embodiments, the light flux control member integrally formed by resin molding has been described. However, the light flux control member may not be integrally formed by resin molding. For example, although not particularly illustrated, the light flux controlling member has a deflection surface, a first ridge row, and a second ridge row. The first ridge row has a plurality of first ridges arranged such that each ridge line is parallel to each other and located on the same first virtual plane. The second ridge row has a plurality of second ridges arranged such that the ridge lines are parallel to each other and located on the same second virtual plane. The surface of these 1st protruding item | line and 2nd protruding item | line is a mirror surface. The ridge line of the first ridge and the ridge line of the second ridge are perpendicular to each other. The first ridge row has a function equivalent to the first prism row 340, 440 of each of the above embodiments, and the second ridge row has a function equivalent to the second prism row 360, 460. In this case, the collimated light deflected by the polarization plane is linearly incident on the surface of the first ridge row and reflected linearly. Further, the collimated light reflected by the first ridge row is incident on the second ridge row in a planar shape and reflected in a planar shape. In this way, by separately forming each component, the emission surface becomes unnecessary.

  The surface light source device of the present invention can be applied to, for example, a backlight of a liquid crystal display device or general illumination.

DESCRIPTION OF SYMBOLS 10 Surface light source device 20 Laser light source 30 Collimator lens 40 Light beam control member 41 Incident surface 42 1st prism row | line | column 43 2nd prism row | line | column 44 Output surface 45 1st prism 46 2nd prism 100 Surface light source device 200 Laser light source 300,400, 500 Luminous flux control member 320, 520 Deflection surface 340, 440 First prism row 341 First prism 342 First reflection surface 343 First inclined surface 344 First ridge line 345 First virtual plane 346 First valley line 360, 460 Second prism Row 361 Second prism 362 Second reflecting surface 363 Second inclined surface 364 Second ridgeline 365 Second virtual plane 366 Second valley 380,590 Outgoing surface C1, C2 Curve L Laser light

Claims (10)

A surface light source device comprising: a light source that emits collimated light having polarization characteristics; and a light beam control member that is disposed above the light source and controls an optical path of the collimated light,
The light flux controlling member is
An incident surface on which the collimated light emitted from the light source is incident on the light flux controlling member;
A reflecting surface that reflects the collimated light incident from the incident surface upward;
A deflecting surface that deflects the collimated light reflected by the reflecting surface by reflection ;
A first prism array that linearly enters the collimated light deflected by the deflection surface and reflects the linearly; and
A second prism row that causes the collimated light reflected by the first prism row to be internally incident in a planar shape and reflected in a planar shape;
An emission surface that emits the collimated light reflected by the second prism row upward ,
The first prism row has a plurality of first prisms arranged such that each ridge line is parallel to each other and located on the same first virtual plane,
The second prism row has a plurality of second prisms arranged such that each ridge line is parallel to each other and located on the same second virtual plane,
The ridge line of the first prism and the ridge line of the second prism are perpendicular to each other,
The collimated light traveling to the reflecting surface from the incident surface, it proceeds along the second virtual plane,
Surface light source device.   The surface light source device according to claim 1, wherein the light source is a laser light source.   The surface light source device according to claim 1, wherein a dihedral angle between the deflection surface and the first virtual plane is an acute angle.   The surface light source device according to claim 1, wherein a dihedral angle between the first virtual plane and the second virtual plane is an acute angle.   5. The surface light source device according to claim 1, wherein a thickness between the emission surface and the second virtual plane gradually decreases as the distance from the first virtual plane increases.   The surface light source device according to claim 1, wherein the emission surface and the second virtual plane are parallel to each other.   The surface light source device according to claim 1, wherein the deflection surface is a refractive surface. The light flux controlling member is made of a non-birefringent optical resin, the surface light source device according to any one of claims 1-7. A surface light source device comprising: a light source that emits collimated light having polarization characteristics; and a light beam control member that is disposed above the light source and controls an optical path of the collimated light,
The light flux controlling member is
A reflecting surface that reflects the collimated light emitted from the light source upward;
A deflecting surface that deflects the collimated light reflected by the reflecting surface by reflection ;
A first ridge row that linearly enters the collimated light deflected by the deflection surface and reflects the linearly;
The collimated light reflected by the first ridge row is incident in a planar shape, and the second ridge row is reflected in a planar shape,
The first ridge row has a plurality of first ridges arranged such that each ridge line is parallel to each other and located on the same first virtual plane,
The second ridge row has a plurality of second ridges arranged such that each ridge line is parallel to each other and located on the same second virtual plane,
The ridge line of the first ridge and the ridge line of the second ridge are perpendicular to each other,
The collimated light emitted from the light source and incident on the reflecting surface travels along the second virtual plane.
Surface light source device. A display device comprising: the surface light source device according to any one of claims 1 to 9 ; and a display member that is irradiated with light emitted from the surface light source device.