• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
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    • 专利摘要:
    A backlight unit includes a housing having an opening in which is disposed a liquid crystal display device, a light source disposed within the housing, and an optical member disposed within the housing, pointing a path light from the light source to the liquid crystal display device, and having a triangular prism portion of a translucent material. The prism portion has a first side wall as an input wall on which light from the light source is incident, another side wall as an output wall emitting light to the liquid crystal display device. and yet another side wall as a reflecting wall reflecting light incident on the input wall to the exit wall within the prism portion.
    公开号:FR3062491A1
    申请号:FR1850526
    申请日:2018-01-23
    公开日:2018-08-03
    发明作者:Kenji Yagi；Hidetoshi Mukojima；Naohisa MURATA；Naoto Tsubakihara
    申请人:Yazaki Corp；
    IPC主号:
    专利说明:

    Holder (s):
    YAZAKI CORPORATION.
    O Extension request (s):
    Agent (s): BREVALEX Limited liability company.
    FR 3 062 491 - A1 (54) BACKLIGHT UNIT AND HEAD-UP DISPLAY DEVICE.
    (57) A backlight unit includes a housing having an opening in which is arranged a liquid crystal display device, a light source arranged inside the housing, and an optical member arranged inside the housing, pointing a light path from the light source to the liquid crystal display device, and having a triangular prism portion made of a translucent material. The prism portion has a first side wall serving as an inlet wall on which the light from the light source is incident, another side wall as an outlet wall emitting light towards the liquid crystal display device , and yet another side wall as a reflecting wall reflecting the light incident on the inlet wall towards the outlet wall inside the prism portion.
    S64090 CM-P i
    BACKLIGHT UNIT AND HEAD-UP DISPLAY DEVICE
    Context of the invention
    1. Field of the invention
    The present invention relates to a backlight unit and a head-up display device.
    2. Description of the related art
    Backlight units used, for example, for head-up display devices are known. Japanese published patent application No. 2016-065,907 discloses a technology relating to a backlight unit which includes a plurality of focusing lenses which focus beams of light emitted from an image of a light source onto a region of display of a liquid crystal display element.
    More optical devices such as lenses or mirrors in a backlight unit can lead to a larger device size. It is desirable that backlight units have a smaller device size.
    Summary of the invention
    It is an object of the present invention to provide a backlight unit and a head-up display device which can achieve a smaller device size.
    S64090 CM-P
    A backlight unit according to one aspect of the present invention includes a housing having an opening in which is arranged a liquid crystal display device; a light source disposed inside the housing; and an optical member disposed within the housing and configured to point a light beam path of light beams emitted from the light source to the liquid crystal display device, wherein the optical member has a portion prism which is made of a translucent material to have a triangular prism shape, the prism portion has a first side wall serving as an inlet wall on which the light beams emitted by the light source are incident, another side wall serving as an exit wall from which light beams are emitted towards the liquid crystal display device, and yet another side wall serving as a reflecting wall which reflects the light beams which have been incident on the light wall inlet to the outlet wall inside the prism portion, and at least one side wall from among the inlet wall, the exit wall and the reflecting wall has a curved surface shape having an optical property which changes a degree of growth or decline of a beamwidth of beams of light passing through said one side wall in an increasing or decreasing direction.
    According to another aspect of the present invention, in the backlight unit, it is preferable that
    S64090 CM-P the assembly of the entry wall, the exit wall and the reflecting wall has a shape of curved surface having the optical property.
    According to yet another aspect of the present invention, in the backlight unit, it is preferable that the curved surface shape of the inlet wall, the outlet wall and the reflective wall is a convex shape curving towards the outside with respect to the prism portion.
    A head-up display device according to yet another aspect of the present invention includes a liquid crystal display device; and a backlight unit, wherein the backlight unit includes a housing having an opening in which is arranged a liquid crystal display device; a light source disposed inside the housing; and an optical member arranged inside the housing and configured to point a light beam path of light beams emitted by the light source towards the liquid crystal display device, the optical member comprises a prism portion which is made of a translucent material to have a triangular prism shape, the prism portion has a first side wall serving as an inlet wall on which the light beams emitted by the light source are incident, another side wall serving as an exit wall from which beams of light are emitted to the liquid crystal display device, and yet another side wall serving as a reflecting wall which
    S64090 CM-P reflects the beams of light which have been incident on the entry wall towards the exit wall inside the prism portion, and at least one side wall among the entry wall, the wall of exit and the reflective wall has a curved surface shape having an optical property which changes a degree of growth or decline of a beam width of light beams passing through said one side wall in an increasing or decreasing direction.
    The above and other objects, features, advantages and technical and industrial significance of the present invention will be better understood on reading the following detailed description of the presently preferred embodiments of the invention, when considered in relation with the accompanying drawings.
    Brief description of the drawings
    Figure 1 is a diagram illustrating a general configuration of a head-up display device according to an embodiment of the present invention;
    Figure 2 is a perspective view of a projector unit according to the embodiment;
    Figure 3 is a perspective view of a housing according to the embodiment;
    Figure 4 is a transparent side view of the projector unit according to the embodiment;
    Figure 5 is a perspective view of a diffusion lens according to the embodiment;
    S64090 CM-P Figure 6 is a plan view of an optical member according to the embodiment;
    Figure 7 is a perspective view of the optical member according to the embodiment;
    Figure 8 is a sectional view of the optical member according to the embodiment;
    Figure 9 is a longitudinal sectional view of the optical member according to the embodiment;
    Figure 10 is another sectional view
    longitudinal of The organ optigue according to the fashion of production ; the figure 11 is still a other view sectional longitudinal of The organ optigue according to the fashion of
    production ;
    Fig. 12 is a sectional view illustrating an example of a light beam path in the backlight unit according to the embodiment;
    Fig. 13 is a perspective view illustrating an example of a light beam path in the backlight unit according to the embodiment; and Fig. 14 is another perspective view illustrating an example of the light beam path in the backlight unit according to the embodiment.
    Detailed description of the preferred embodiment
    A backlight unit and a head-up display device according to an embodiment of the present invention are fully described below with reference to the accompanying drawings. The mode of
    S64090 CM-P realization is presented for illustration purposes only and is not intended to limit the scope of the present invention. The components described in the embodiment below include components which can be readily imagined by those skilled in the art or components which are substantially identical to each other.
    Mode of realization
    An embodiment will be described with reference to Figures 1 to 14. The present embodiment relates to a backlight unit and a head-up display device. Figure 1 is a diagram illustrating a general configuration of the head-up display device according to the embodiment, Figure 2 is a perspective view of a projector unit according to the embodiment, Figure 3 is a view perspective of a housing according to the embodiment, FIG. 4 is a side of the projector unit transparent view of according to the embodiment, FIG. 5 is a perspective view of a diffusion lens according to the embodiment embodiment, Figure 6 is a plan view of an optical member according to the embodiment, and Figure 7 is a perspective view of the optical member according to the embodiment.
    As
    The figure illustrates
    1, this head-up display device according to the embodiment includes a mirror 2, a liquid crystal display device 10, a backlight unit 20 and a windshield WS. The WS windshield is an example of a
    S64090 CM-P reflective member has at a front dimension of a vehicle with respect to a driver 200. The windshield WS is a transflective member which transmits certain beams of light and reflects the other beams of light. The WS windshield can be coated with a transflective coating.
    The liquid crystal display device 10 and the backlight unit 20 constitute a projector unit 4 which projects an image. The backlight unit 20 emits light beams on the back side of the liquid crystal display device 10, and an image displayed on the liquid crystal display device 10 is projected by the light beams. The mirror 2 reflects the image projected by the projector unit 4 on the windshield WS. The mirror 2 is, for example, an aspherical mirror. The image projected by the headlamp unit 4 is reflected on the mirror 2 and the windshield WS, thus forming a virtual image 3. The virtual image 3 seen by the driver 200 is formed at a front side of the vehicle compared to the windshield WS.
    As illustrated in Figure 2, the liquid crystal display device 10 includes a holding member 11 and a liquid crystal display unit 12. The holding member 11 holds the liquid crystal display unit 12 and is fixed to a housing 21 which will be described later. The holding member 11 is a rectangular plate type member having an opening 11a. The opening 11a in the present embodiment is an opening
    S64090 CM-P rectangular. The longitudinal direction of the opening 11a corresponds to the longitudinal direction of an image to be projected on the windshield WS. The longitudinal direction of the image to be projected on the windshield WS typically corresponds to the lateral direction of the vehicle. The liquid crystal display unit 12 is fixed to the holding member 11 so that it closes the opening 11a. The liquid crystal display unit 12 is, for example, an active matrix liquid crystal display (TFT LCD). The liquid crystal display unit 12 creates an image to be displayed as a virtual image 3.
    The backlight unit 20 includes the housing 21. The housing 21 and the holding member 11 are made of a material such as a metal or a resin which does not transmit beams of light. As illustrated in Figure 3, the housing 21 includes a main body 22 and a leaning portion 23. The main body 22 and the leaning portion 23 are tubular components and are integrated. The main body 22 is a rectangular tubular component and one end thereof remote from the leaning portion 23 is closed. The leaning portion 23 leans in relation to the main body 22. In other words, the housing 21 is a tubular member having a curved portion at the joint between the main body 22 and the leaning portion 23. The leaning portion 23 has an opening 23a at an end remote from the main body 22. The opening 23a in the present embodiment is a rectangular opening. The opening 23a is more
    S64090 CM-P large that the opening 11a of the liquid crystal display device 10. The liquid crystal display device 10 is fixed to the housing 21 and closes the opening 23a.
    As shown in Figure 4, the backlight unit 20 further includes a light emitting diode (LED) substrate 30, a lens array 40, a diffusion lens 50, and an optical member 60. The LED substrate 30 is arranged at the innermost portion of the housing 21. In the housing 21, the lens array 40, the diffusion lens 50, and the optical member 60 are arranged in this order from the LED substrate 30 to the opening 23a. The LED substrate 30 includes a substrate body 31 and a plurality of LEDs 32. The LEDs 32 are light emitting diodes and are attached to the substrate body 31. The LEDs 32 serve as a light source for the backlight unit 20. The LEDs 32 are aligned linearly with a certain spacing therebetween on the substrate body 31 according to the present embodiment. The LEDs 32 are aligned in a direction of the width W (see Figure 2) of the housing 21. The direction of the width W of the housing 21 corresponds to the direction in the page in Figure 4. The substrate body 31 includes a control circuit for controlling the LEDs 32. The control circuit controls the switching on / off of the LEDs 32 and the brightness of the LEDs 32.
    The lens array 40 is disposed near the LEDs 32 facing the latter. The lens array 40 is a set of condenser lenses
    S64090 CM-P ίο which group together beams of light emitted by the LEDs 32. The lens array 40 includes a plurality of lenses 41. The lenses 41 are arranged in the direction of the width W of the housing 21 with a certain spacing between them . The individual lenses 41 are arranged coaxially with respect to the corresponding LEDs 32. The lenses 41 convert light beams emitted by the LEDs 32 into parallel light beams and emit them towards the diffusion lens 50.
    The scattering lens 50 diffuses the light beams from the lens array 40 and emits the scattered light beams towards the optical member 60. As illustrated in FIG. 5, the scattering lens 50 is a microlens array including a plurality of microlenses 52. The diffusion lens 50 includes a frame 51 and many microlenses 52. The frame 51 is a frame-like member having a rectangular configuration. The microlenses 52 are arranged in an array of rows and columns in the direction of the width W and a direction of the height H (see FIG. 2) of the housing 21. The microlenses 52 are held by the frame 51. The microlenses 52 scatter light beams from the lens array 40 and emit the scattered light beams to the optical member 60. The scattering lens 50 has a function of producing a uniform light distribution with respect to brightness and a function scattering of light beams in multiple directions.
    S64090 CM-P
    Referring again to Figure 4, the optical member 60 is disposed in the leaning portion 23. The optical member 60 comprises a prism portion 60A having the shape of a triangular prism. The prism portion 60A has side walls which mainly constitute the shape of a triangular prism, which are an inlet wall 61, an outlet wall 62 and a reflective wall 63. As illustrated in FIGS. 6 and 7, the optical member 60 according to the present embodiment comprises an articulation surface 64 which joins the outlet wall 62 and the reflective wall 63.
    The optical member 60 is arranged in an internal space of the leaning portion 23 so that the axial direction of the prism portion 60A agrees with the direction of the width W of the housing 21. In other words, the member optic 60 is arranged so that the inlet wall 61, the outlet wall 62 and the reflective wall 63 extend in the direction of the width W of the housing 21. The optical member 60 is arranged so that the inlet wall 61 is opposite the diffusion lens.
    Beams of light emitted by
    LEDs 32, which serve as a light source, are incident on
    1 optical member 60 from the inlet wall 61 from the inlet wall 61, the outlet wall 62 and the reflecting wall.
    The two ends of the optical member 60 are held by internal walls of the housing 21.
    The optical member 60 is made of a translucent material. The optical member 60 according to the present mode
    S64090 CM-P of realization is made of a colorless transparent material. Examples of the material for the optical member 60 include synthetic resins such as a polycarbonate resin and an acrylic resin. The inlet wall 61, the outlet wall 62 and the reflecting wall 63 of the optical member 60 according to the present embodiment each have a curved external surface.
    Figure 8 illustrates a section in section along line VIII-VIII of Figure 6. The section illustrated in Figure 8, namely, a section orthogonal to the axial direction of the prism portion 60A, is designated by "cross section " As illustrated in Figure 8, the cross-sectional shape of the inlet wall 61, the outlet wall 62 and the reflective wall 63 in the cross section is a curved shape.
    More specifically, the inlet wall 61, the outlet wall 62 and the reflective wall each have a convex shape curving outward with respect to the prism portion 60A. The section illustrated in the cross-section at the center of the prism portion 60A in the axial direction.
    Cross sections at other positions of the prism portion 60A in the axial direction have the same convex shape as the inlet wall 61, the outlet wall 62 and the reflective wall 63. In other words, the surface outer of the inlet wall 61, the outlet wall 62 and the reflective wall 63 is a generally convex surface curving outwardly relative to the prism portion 60A.
    S64090 CM-P
    As illustrated in Figure 8, the curvature of the reflective wall 63 in the cross-sectional shape is relatively moderate compared to the curvature of the inlet wall 61 and the outlet wall 62 in the cross-sectional shape. The reflecting wall 63 has a shape of curved section which is practically a straight line.
    Figure 9 illustrates a section in section along line IX-IX of Figure 4. The section in section along the axial direction of the prism portion 60A as illustrated in Figure 9 is designated by "longitudinal section". As illustrated in FIG. 9, the cross-sectional shape of the inlet wall 61 in the longitudinal section is a convex shape curving outwards relative to the prism portion 60A. The cross-sectional shape of the inlet wall 61 is symmetrical with respect to a central line C1. The central line C1 is a line drawn at the center of the prism portion 60A in the axial direction. In the sectional shape of the inlet wall 61, the central portion in the axial direction is the most protruding. In the sectional shape of the inlet wall 61, the curvature of end portions 61e in the axial direction is greater than the curvature of this central portion 61c.
    FIG. 10 illustrates a section in section along line XX of FIG. 4. As illustrated in FIG. 10, the sectional shape of the outlet wall 62 in the longitudinal section is a convex shape bending outwardly relative to the prism portion 60A. The cross-sectional shape of the wall of
    S64090 CM-P output 62 is symmetrical about a central line C2. The central line C2 is a line drawn in the center of the prism portion 60A in the axial direction. In the sectional shape of the outlet wall 62, the central portion in the axial direction is the most protruding. In the sectional shape of the outlet wall 62, the curvature of end portions 62e in the axial direction is greater than the curvature of this central portion 62c.
    Figure 11 illustrates a section in section along line XI-XI of Figure 4. As illustrated in Figure 11, the sectional shape of the reflecting wall 63 in the longitudinal section is a convex shape curving outward relative to the prism portion 60A. The cross-sectional shape of the reflecting wall 63 is symmetrical with respect to a central line C3. The central line C3 is a line drawn in the center of the prism portion 60A in the axial direction. In the sectional shape of the reflecting wall 63, the central portion in the axial direction is the most protruding. In the sectional shape of the reflecting wall 63, the curvature of end portions 63e in the axial direction is greater than the curvature of this central portion 63c. In the optical member 60 according to the present embodiment, the curvature of the reflecting wall 63 in the sectional shape is smaller than that of the inlet wall 61 and the outlet wall 62 in comparison with one the other in the same position in the axial direction.
    S64090 CM-P
    Figure 12 illustrates a section of the backlight unit 20 and an example of a light beam path. The section illustrated in FIG. 12 is orthogonal to the axial direction of the optical member 60 and in section at the center of the optical member 60 in the axial direction. With reference to FIG. 12, a function of adjusting a beam width W1 by the optical member 60 in a view in a section orthogonal to the axial direction of the optical member 60 will be described.
    In FIG. 12, light beams Lt1 traversing the section are indicated by solid lines. Light beams Lt2, which are light beams other than light beams Lt1, traversing the section are indicated by dashed lines. As illustrated in FIG. 12, the light beams Ltl and Lt2 emitted by the LEDs 32 and diffused by the diffusion lens 50 are incident on the prism portion 60A from the inlet wall 61. The light beams passing through the prism portion 60A from the inlet wall 61 are reflected on the reflective wall 63 towards the outlet wall 62. In other words, the reflective wall 63 functions as a reflective surface which reflects the light beams which have been incident on the inlet wall 61 in the direction of the outlet wall 62 inside the prism portion 60A. The light beams reflected on the reflecting wall 63 are emitted from the outlet wall 62 to the external space.
    S64090 CM-P
    The entry wall 61 changes the degree of increase or decrease of the beam width W1 in a decreasing direction.
    The beam width W1 is a width of a light beam path on the section orthogonal to the axial direction of the optical member 60.
    The degree of increase or decrease in the beamwidth W1 is typically a rate of increase or decrease in the beam path
    W1 along an optical axis XI. The growth or decrease rate is, for example, a growth rate or a decrease rate of the beam path W1 per unit of length of the optical axis XI. In the present description, the divergence of light beams as the beams progress is designated by increase in beamwidth Wl, while the convergence of light beams as the beams progress is designated by decrease in beamwidth Wl .
    The change in the degree of increase or decrease in beamwidth W1 towards an increasing direction through the walls 61, 62 and 63 includes at least one of the elements (1) to (3) below.
    (1) Accentuation of a growth degree of the beamwidth Wl of incoming light beams progressing with an increasing beamwidth Wl.
    In other words, the light beams are more divergent.
    (2) Change of incoming light beams progressing with a decreasing or constant beam width Wl into light beams progressing with an increasing beam width Wl.
    S64090 CM-P
    In other words, converging beams of light or parallel beams of light are changed to diverging beams of light.
    (3) Reduction of a degree of decrease in the beam width W1 of incoming light beams progressing with a decreasing beam width W1. In other words, the degree of convergence of the light beams is reduced.
    The change in the degree of increase or decrease of the beam width W1 towards a decreasing direction through the walls 61, 62 and 63 includes at least one of the elements (4) to (6) below.
    (4) Increasing a degree of decrease in the beam width W1 of incoming beams of light progressing with a decreasing beam width W1. In other words, beams of light are more converged.
    (5) Change of incoming light beams progressing with an increasing or constant beam width W1 into light beams progressing with a decreasing beam width W1. In other words, diverging light beams or parallel light beams are changed to converging light beams.
    growth of the beam width W1 of incoming light beams progressing with an increasing beam width W1.
    In other words, the degree of divergence of the light beams is reduced.
    The inlet wall 61 according to the present embodiment carried out the above operation.
    In
    S64090 CM-P in other words, the entry wall 61 refracted light beams to reduce the degree of divergence of the light beams. In the following description, the light beams Ltl which pass through the section are designated by: incoming light beams Ltll progressing towards the inlet wall 61; refracted light beams Ltl2 progressing from the inlet wall 61 to the reflecting wall 63 inside the prism portion 60A; reflected light beams Ltl3 reflected on the reflecting wall 63 and progressing towards the exit wall 62 inside the prism portion 60A; and outgoing light beams Ltl4 emitted from the exit wall 62. The entry wall 61 changes the degree of growth of the beam width Wl of the incoming light beams Lt11 so that the degree of growth of the beam width Wl of the refracted light beams Ltl2 becomes smaller than that of the incoming light beams Ltll. Normal shapes or directions at portions of the inlet wall 61 are determined such that the degree of divergence of the refracted light beams Lt12 becomes smaller than that of the incoming light beams Lt11. Normal shapes or directions at portions of the inlet wall 61 are determined, for example, from the angles at which the incoming light beams Ltll from the scattering lens 50 are incident on the inlet wall 61 , the refractive index of the material of the optical member 60, and
    S64090 CM-P target refraction angles of Ltl2 refracted light beams.
    The reflecting wall 63 according to the present embodiment performs the above operation (6). In other words, the reflecting wall 63 reflects beams of light to reduce the degree of divergence of the beams of light. The reflecting wall 63 changes the degree of growth of the beam width W1 of the refracted light beams Ltl2 so that the degree of growth of the beam width W1 of the reflected light beams Ltl3 becomes smaller than that of the light beams refracted Ltl2. Normal shapes or directions at portions of the reflecting wall 63 are determined such that the degree of divergence of the reflected light beams Ltl3 becomes smaller than that of the refracted light beams Ltl2. In addition, the reflecting wall 63 according to the present embodiment is configured to totally reflect the refracted light beams Ltl2. Normal shapes or directions at portions of the reflecting wall 63 are determined such that the reflecting wall 63 fully reflects the refracted light beams Ltl2. Normal shapes or directions at portions of the reflective wall 63 are determined, for example, from the angles at which the refracted light beams Ltl2 are incident on the reflective wall 63, the refractive index of the material
    S64090 CM-P of the optical member 60, and of the target angles of refraction of the reflected light beams Ltl3.
    The outlet wall 62 according to the present embodiment from above.
    In other words, the exit wall refracts the light beams to reduce the degree of divergence of the light beams.
    Normal shapes or directions at portions of the exit wall are determined such that the degree of growth of the beam width W1 of the outgoing light beams Ltl4 becomes smaller than that of the reflected light beams Ltl3. Normal shapes or directions at portions of the outlet wall 62 are determined, for example, from the angles at which the reflected light beams Ltl3 are incident on the outlet wall 62, the refractive index of the material of the optical member 60, and target angles of refraction of the outgoing light beams Ltl4.
    The outgoing light beams Ltl4 emitted by the outlet wall 62 are incident on the dorsal face of the liquid crystal display device 10. An image displayed on the liquid crystal display device 10 is projected by the outgoing light beams Ltl4. The image projected from the liquid crystal display device 10 is reflected on the mirror 2 in the direction of the windshield WS. The outgoing light beams Ltl4 are divergent light beams which progress with increasing beam width W1. So the image projected from
    S64090 CM-P the liquid crystal display device 10 expands towards the windshield WS.
    The function of adjusting the beam width W1 by the prism portion 60A is the same at other locations in section in the axial direction. The beam width W1 can be adjusted by different degrees between the central portion and end portions of the prism portion 60A in the axial direction.
    A function of adjusting a beam width W2 which extends in the axial direction of the optical member 60 is described below.
    As illustrated in FIGS. 13 and 14, the incoming light beams Ltll going towards the entry wall progress from the diffusion lens towards the entry wall with a beam width
    W2 increasing which extends in the axial direction.
    The inlet wall 61 according to the present embodiment above.
    In other words, the inlet wall 61 refracts light beams to reduce the degree of divergence of the light beams. The input wall 61 changes the degree of growth of the beamwidth W2 of the incoming light beams Ltll so that the degree of growth of the beamwidth W2 of the refracted light beams Ltl2 becomes smaller than that of the beams incoming light Ltll. Normal shapes or directions at portions of the inlet wall 61 are determined such that the degree of divergence of the refracted light beams Ltl2 becomes smaller than that of the
    S64090 CM-P incoming light beams Ltll. Normal shapes or directions at portions of the inlet wall 61 are determined, for example, from the angles at which the incoming light beams Ltll from the scattering lens 50 are incident on the inlet wall 61 , the refractive index of the material of the optical member 60, and the target refractive angles of the refracted light beams Ltl2.
    The reflecting wall 63 according to the present embodiment performs the above operation (6). In other words, the reflecting wall 63 reflects beams of light to reduce the degree of divergence of the beams of light. The reflecting wall 63 changes the degree of growth of the beam width W2 of the refracted light beams Ltl2 so that the degree of growth of the beamwidth W2 of the reflected light beams Ltl3 becomes smaller than that of the light beams refracted Ltl2. Normal shapes or directions at portions of the reflecting wall 63 are determined such that the degree of divergence of the reflected light beams Ltl3 becomes smaller than that of the refracted light beams Ltl2. As described above, the reflecting wall 63 according to the present embodiment is configured to totally reflect the refracted light beams Ltl2. Normal shapes or directions at portions of the reflecting wall 63 are determined, for example, from the angles at which the beams of
    S64090 CM-P refracted light Ltl2 are incident on the reflecting wall 63, the refractive index of the material of the optical member 60, and of the target reflection angles of the reflected light beams Ltl3.
    The outlet wall 62 according to the present embodiment from above.
    In other words, the exit wall refracts the light beams to reduce the degree of divergence of the light beams.
    Normal shapes or directions at portions of the exit wall are determined such that the degree of growth of the beamwidth W2 of the outgoing light beams Ltl4 becomes smaller than that of the reflected light beams Ltl3. Normal shapes or directions at portions of the outlet wall 62 are determined, for example, from the angles at which the reflected light beams Ltl3 are incident on the outlet wall 62, the refractive index of the material of the optical member 60, and target angles of refraction of the outgoing light beams Ltl4.
    As described above,
    The backlight unit 20 according to the present embodiment includes the housing 21, the LEDs 32 serving as a light source, and the optical member 60.
    The housing 21 has the opening 23a in which the liquid crystal display device 10 is disposed.
    The
    LEDs 32 are arranged inside the housing 21.
    The optical member 60 is disposed inside the housing 21 and configured to point the beam light beam path
    S64090 CM-P of light emitted by the LEDs 32 towards the liquid crystal display device 10. The optical member 60 comprises the prism portion 60A which is constituted
    of a material translucent for: r have a made of triangular prism. The prism portion 60A behaves a first side wall serving of wall input 61, another side wall serving of wall Release 62, and even another wall lateral servingof wall reflective 63. The entrance wall 61 East a wall
    side on which the light beams emitted by the LEDs 32 are incident.
    The outlet wall 62 is a side wall from which beams of light are emitted towards the liquid crystal display device 10. The reflecting wall 63 is a side wall which reflects the beams of light which have been incident on the wall inlet 61 to the outlet wall 62 inside the prism portion 60A. At least one side wall among the inlet wall 61, the outlet wall 62 and the reflective wall 63 has a curved surface shape having an optical property which changes the degree of increase or decrease of the beam width of beams of light passing through the first side wall in an increasing or decreasing direction.
    The optical member 60 according to the present embodiment comprises the reflecting wall 63 which reflects the light beams coming from the LEDs 32. The optical member 60 further comprises the inlet wall 61 and the outlet wall 62, including at less
    S64090 CM-P one can change, by refraction, the degree of increase or decrease of the beam widths W1 and W2 in an increasing or decreasing direction. In other words, the optical member 60 has two optical surfaces which can change the degree of increase or decrease of the beam widths W1 and W2 in an increasing or decreasing direction, and has a reflecting surface which reflects beams of light. in the optical member 60. This configuration allows the optical member 60 to implement the functions of a plurality of devices such as lenses and mirrors in a single member. Thus, the backlight unit 20 according to the present embodiment can have a smaller device size.
    At least one side wall among the inlet wall 61, the outlet wall 62 and the reflective wall 63 has a curved surface shape having an optical property which changes the degree of increase or decrease of the beam width of beams of light passing through the at least one side wall in an increasing or decreasing direction. The passage of light beams through a side wall includes the passage of light beams through the side wall from the outside to the inside of the prism portion 60A, the passage of light beams through the side wall from the inside outside of the prism portion 60A, and the reflection of light beams on the side surface inside the prism portion 60A.
    S64090 CM-P
    Side walls having a curved surface shape are advantageous in terms of obtaining the desired optical properties. When, for example, the reflective wall 63 has a curved surface shape, the shape is determined so that the reflective wall 63 changes the degree of growth or decay of the beamwidths W1 and W2 of the reflected light beams Ltl3 reflected on the reflective wall 63 to a certain desired degree.
    When the inlet wall 61 and the outlet wall 62 have a curved surface shape, the shape is determined so that the walls 61 and change the degree of increase or decrease of the beamwidths W1 and
    W2 of the refracted light beams Ltl2 and the outgoing light beams Ltl4 refracted by the walls and to a certain degree desired. It is desirable that the curved surface shape of the walls 61, 62 and is determined so that the walls produce a uniform light distribution with respect to the brightness in the light beam path.
    The inlet wall 61, the outlet wall and the reflective wall 63 of the optical member 60 according to the present embodiment all have a shape of curved surface having an optical property which changes the degree of growth or decrease of beam width. In other words, each of the three walls 61, 62 and 63 of the optical member 60 according to the present embodiment can change the degree of increase or decrease of the beamwidths W1 and
    W2. This configuration is advantageous
    S64090 CM-P for the optical organ 60 according to this mode of
    achievement in terms of obtaining of properties optical desired.The surface shape curved of the wall input 61, from the wall of exit 62 and of the wall
    reflective 63 of the optical member 60 according to the present embodiment is a convex shape curving outwards relative to the prism portion 60A.
    The optical member 60 according to the present embodiment can correctly guide beams of light emitted by the LEDs 32 towards the liquid crystal display device 10 by adjusting the beam widths W1 and W2 in stages.
    The head-up display device 1 according to the present embodiment includes the liquid crystal display device 10 and the backlight unit 20 above. The head-up display device 1 according to the present embodiment can have a smaller device size.
    Modification of the embodiment
    The curved surface shape of the inlet wall 61, the outlet wall 62 and the reflective wall 63 is curved both in cross section and in longitudinal section in the above embodiment, but without limit it. The cross-sectional or longitudinal sectional shape can be a linear shape. For example, the cross-sectional shape of the reflecting wall 63 in cross-section can be a
    S64090 CM-P lmeaire form. The shape of the curved surface of the inlet wall 61, the outlet wall 62 and the reflective wall 63 is not limited to a convex shape curving outwards relative to the prism portion 60A, and conversely, the curved surface shape can be a convex shape curving inwardly relative to the prism portion 60A.
    In the above embodiment, the inlet wall 61, the outlet wall 62 and the reflective wall 63 all have the shape of a curved surface, without being limited thereto. At least one wall among the inlet wall 61, the outlet wall 62 and the reflective wall 63 may have a flat shape.
    In the above embodiment, the reflective wall 63 completely reflects the refracted light beams Ltl2, without being limited thereto. The reflection of the refracted light beams Ltl2 on the reflecting wall 63 may not be a total reflection.
    The content disclosed in the above embodiment and modification can be appropriately combined and implemented.
    The backlight unit and the head-up display device according to the present embodiment includes a housing having an opening in which a liquid crystal display device is disposed, a light source disposed inside the housing, and an optical member disposed within the housing and configured to point a light beam path of light beams emitted from the light source to the device
    S64090 CM-P liquid crystal display. The optical member includes a prism portion which is made of a translucent material to have a triangular prism shape. The prism portion has a first side wall serving as an entry wall on which the light beams emitted by the light source are incident, another side wall serving as an exit wall from which light beams are emitted towards the liquid crystal display device, and yet another side wall serving as a reflecting wall which reflects beams of light which have been incident on the entry wall towards the exit wall inside the prism portion .
    At least one side wall among the entry wall, the exit wall and the reflecting wall has a curved surface shape having an optical property which changes the degree of increase or decrease of the beamwidth of light beams passing through. across the first side wall in an increasing or decreasing direction. The backlight unit and the head-up display device according to the present embodiment can be configured by a smaller number of components, thereby achieving a smaller device size.
    Although the invention has been described in terms of specific embodiments for clear and complete disclosure, the appended claims should not be so limited but should be
    S64090 CM-P interpreted as integrating all the modifications and alternative constructions which may appear to a person skilled in the art, which enter rightly into the basic teaching set out here.
    S64090 CM-P
    权利要求:
    Claims (3)
    [1" id="c-fr-0001]
    1. Backlight unit comprising:
    a housing having an opening in which is arranged a liquid crystal display device;
    a light source disposed inside the housing; and an optical member disposed inside the housing and configured to point a beam path at the light beams emitted by the light source towards the liquid crystal display device, wherein the optical member comprises a prism portion which is made of a translucent material to have a triangular prism shape, the prism portion has a first side wall serving as an inlet wall on which the light beams emitted by the light source are incident, another side wall serving as an exit wall from which light beams are emitted to the liquid crystal display device, and yet another side wall serving as a reflecting wall which reflects the light beams which have been incident on the entry wall towards the outlet wall inside the prism portion, and at least one side wall among the inlet wall, the wall of s nettle, and the reflecting wall has a curved surface shape having an optical property which changes a degree of growth or decrease of a beamwidth
    S64090 CM-P of light beams passing through said one side wall in an increasing or decreasing direction.
    [2" id="c-fr-0002]
    2. Backlight unit according to claim 1, wherein
    The surface outlet assembly
    [3" id="c-fr-0003]
    3.
    of the entry wall, the wall of and the curved
    Unity Claim Form
    2, of a reflecting wall having the property of backlighting in which the curved surface of the has an optical shape.
    according to the inlet wall, the outlet wall and the reflective wall a convex shape curving outwardly a ratio is to the prism portion.
    Head-up display device comprising liquid crystal display device;
    a backlight unit, in which the unit of which is and backlight includes liquid crystal housing;
    a source inside the liquid light beam housing, one and having an opening in the light display device disposed housing; and optical member configured to be disposed at
    Inside the pointer a path of to the beams of light emitted by towards the display device the crystal source
    S64090 CM-P the optical member has a prism portion which is made of a translucent material to have a triangular prism shape, the prism portion has a first side wall serving as an entry wall on which the light beams emitted by the light source are incident, another side wall serving as an exit wall from which beams of light are emitted towards the liquid crystal display device, and yet another side wall serving as a reflecting wall which reflects the beams of light which have been incident on the entry wall towards the exit wall inside the prism portion, and at least one side wall among the entry wall, the exit wall and the reflecting wall has a shape of a curved surface having an optical property which changes a degree of increase or decrease in the width of a beam of light beams passing through across said one side wall in an increasing or decreasing direction.
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    同族专利:
    公开号 | 公开日
    JP6533540B2|2019-06-19|
    US20180217376A1|2018-08-02|
    CN108363239A|2018-08-03|
    US10114219B2|2018-10-30|
    FR3062491B1|2021-12-03|
    JP2018120807A|2018-08-02|
    DE102018201002A1|2018-08-02|
    CN108363239B|2021-07-02|
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    法律状态:
    2020-01-30| PLFP| Fee payment|Year of fee payment: 3 |
    2020-12-18| PLSC| Publication of the preliminary search report|Effective date: 20201218 |
    2021-01-28| PLFP| Fee payment|Year of fee payment: 4 |
    2022-01-31| PLFP| Fee payment|Year of fee payment: 5 |
    优先权:
    申请号 | 申请日 | 专利标题
    JP2017012798|2017-01-27|
    JP2017012798A|JP6533540B2|2017-01-27|2017-01-27|Backlight unit and head-up display device|
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