[go: up one dir, main page]
More Web Proxy on the site http://driver.im/

WO2011125479A1 - Plaque de guidage de lumière polarisante, dispositif d'éclairage et dispositif d'affichage par projection - Google Patents

Plaque de guidage de lumière polarisante, dispositif d'éclairage et dispositif d'affichage par projection Download PDF

Info

Publication number
WO2011125479A1
WO2011125479A1 PCT/JP2011/056761 JP2011056761W WO2011125479A1 WO 2011125479 A1 WO2011125479 A1 WO 2011125479A1 JP 2011056761 W JP2011056761 W JP 2011056761W WO 2011125479 A1 WO2011125479 A1 WO 2011125479A1
Authority
WO
WIPO (PCT)
Prior art keywords
light guide
light
polarized light
angle
guide plate
Prior art date
Application number
PCT/JP2011/056761
Other languages
English (en)
Japanese (ja)
Inventor
悟郎 齋藤
雅雄 今井
昌尚 棗田
慎 冨永
Original Assignee
日本電気株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 日本電気株式会社 filed Critical 日本電気株式会社
Priority to JP2012509396A priority Critical patent/JPWO2011125479A1/ja
Publication of WO2011125479A1 publication Critical patent/WO2011125479A1/fr

Links

Images

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/28—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00 for polarising
    • G02B27/286—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00 for polarising for controlling or changing the state of polarisation, e.g. transforming one polarisation state into another
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0033—Means for improving the coupling-out of light from the light guide
    • G02B6/0056—Means for improving the coupling-out of light from the light guide for producing polarisation effects, e.g. by a surface with polarizing properties or by an additional polarizing elements
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336—Illuminating devices
    • G02F1/133615—Edge-illuminating devices, i.e. illuminating from the side
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336—Illuminating devices
    • G02F1/13362—Illuminating devices providing polarized light, e.g. by converting a polarisation component into another one

Definitions

  • the present invention relates to a polarization light guide plate from which light having polarization properties is emitted, and more particularly, to a polarization light guide plate of a projection display device typified by a liquid crystal projector.
  • Patent Document 1 discloses a light guide plate that emits light having polarization.
  • the light guide plate includes a first layer having an incident end face on which light from a light source is incident and an emission surface from which the light is emitted, a second layer formed on the emission surface side of the first layer, and a second layer.
  • a third layer made of an anisotropic material is formed, and a plurality of light distribution adjusting units are formed in an interface between the second layer and the first layer.
  • a polarization conversion plate and a reflection plate are formed on the surface of the first layer opposite to the exit surface.
  • the surface of the second layer opposite to the first layer is a prism surface.
  • the prism surface is formed by repeatedly arranging prism structures having a triangular wave cross section.
  • the width of the light distribution adjusting unit becomes smaller as the distance from the light source increases.
  • the interval between the light distribution adjusting units increases as the distance from the light source increases.
  • the third layer is configured such that the first refractive index for P-polarized light and the second refractive index for S-polarized light are different.
  • the first refractive index of the third layer is substantially the same as the refractive index of the first layer and the second layer.
  • the second refractive index of the third layer is larger than the refractive indexes of the first layer and the second layer.
  • the P-polarized light passes through the boundaries of the first layer, the second layer, and the third layer as they are.
  • the P-polarized light incident on the third layer from the second layer is reflected in the direction of the first layer by the surface of the third layer opposite to the second layer.
  • the P-polarized reflected light incident on the second layer from the third layer is reflected in the direction of the third layer by the light distribution adjusting unit, or is transmitted through the first layer and the polarization conversion plate and is reflected by the reflecting plate. Reflected in the direction of one layer. As described above, the P-polarized light is guided between the third layer and the reflection plate, and is converted into S-polarized light by passing through the polarization conversion plate in the light guide process.
  • the S-polarized light traveling from the first layer to the second layer passes through the boundary between the first layer and the second layer as it is.
  • the S-polarized light traveling from the second layer to the third layer is refracted at the boundary between the second layer and the third layer, and enters the third layer.
  • light that is incident on the prism surface of the second layer at a predetermined incident angle is reflected by the prism surface. Then, the light is emitted from the third layer to the outside.
  • a projection display device that irradiates a display element with light from a light source and projects an image formed by the display element by a projection optical system
  • an etendue determined by the light emission cross-sectional area of the light source and the divergence angle of the emitted light Design that takes into account the constraints imposed by That is, in order to use all of the light emitted from the light source as projection light, the product value of the light emission cross-sectional area of the light source and the divergence angle of the emitted light is expressed by the display area of the display element and the F number of the projection optical system. It is necessary to make the value less than the product of the determined capture angle (solid angle). If this condition is not satisfied, part of the light from the light source is not used as projection light.
  • the polarizing light guide plate of the present invention comprises: A light guide including opposing surfaces, and one of these surfaces being an exit surface; A reflective layer provided on the other surface of the opposing surface of the light guide; Phase difference means provided on the exit surface of the light guide; A plurality of anisotropic refracting portions periodically formed in a certain direction along the other surface in the light guide; Each of the plurality of anisotropic refracting portions has a refractive index with respect to the first polarized light that is smaller than a refractive index of the light guide and has a polarization state different from that of the first polarized light.
  • the refractive index is configured to be larger than the refractive index of the light guide
  • the phase difference unit changes the phase of at least one of the first and second polarized lights emitted from the emission surface, and emits circularly polarized light having the same rotation direction or linearly polarized light having the same polarization direction.
  • the lighting device of the present invention is The polarizing light guide plate, And at least one light source for supplying light to an end of the polarizing light guide plate.
  • the projection display device of the present invention is The above lighting device; A display element irradiated with light emitted from the illumination device; A projection optical system for projecting an image formed by the display element.
  • Another projection display device of the present invention is A lighting device of each color of red, green, and blue composed of the lighting device described above, A first display element irradiated with red light emitted from the red illumination device; A second display element irradiated with green light emitted from the green illumination device; A third display element irradiated with blue light emitted from the blue illumination device; A projection optical system for projecting each color image displayed on the first to third display elements.
  • FIG. 2 is a perspective view schematically showing a part of the polarization light guide plate shown in FIG. 1. It is a schematic diagram for demonstrating the emission conditions of the polarizing light-guide plate shown in FIG. It is a schematic diagram for demonstrating the light guide conditions of the polarizing light-guide plate shown in FIG. It is a schematic diagram for demonstrating another light guide condition of the polarizing light guide plate shown in FIG. It is a schematic diagram for demonstrating the conditions (thickness and width) of the magnitude
  • FIG. 1 is a cross-sectional view showing a configuration of a polarizing light guide plate according to the first embodiment of the present invention.
  • FIG. 2 is a perspective view of the polarizing light guide plate shown in FIG.
  • the polarization light guide plate is used in a projection display device typified by a liquid crystal projector, and is provided on the light guide 10 and one surface of the light guide 10.
  • a plurality of anisotropies provided on the boundary surface between the half-wave plate 11 formed, the reflective layer 12 provided on the other surface of the light guide 10, and the reflective layer 12 in the light guide 10 And a refracting portion 13.
  • the light guide 10 is plate-shaped and made of a material having an isotropic refractive index.
  • Refractive index isotropic means that the refractive indexes for the first and second polarized lights (P-polarized light and S-polarized light) having different polarization states are the same.
  • the refractive index of the light guide 10 is n0.
  • the light guide 10 has a plurality of end faces (usually four end faces), and light from the light source is incident on at least one of the end faces.
  • the light source is, for example, a semiconductor light source such as a light emitting diode (LED) or a semiconductor laser (LD), or a light source called a solid light source.
  • the refractive index of the half-wave plate 11 is almost equal to the refractive index n0 of the light guide 10.
  • the half-wave plate 11 has a rectangular shape and is periodically formed in a direction intersecting the longitudinal direction.
  • the longitudinal direction is a direction along the long side of the half-wave plate.
  • the direction intersecting the longitudinal direction is, for example, a direction perpendicular to the end surface where the light source of the light guide 10 is provided.
  • the anisotropic refracting portion 13 is made of a material having an anisotropic refractive index.
  • the refractive index anisotropy indicates that the refractive indexes for the first and second polarized lights are different.
  • the refractive index for the first polarized light is n1
  • the refractive index for the second polarized light is n2.
  • the anisotropic refracting portion 13 is configured to satisfy the condition of n1 ⁇ n0 ⁇ n2.
  • the anisotropic refracting portion 13 has a rectangular parallelepiped shape and is periodically arranged in a direction intersecting with the longitudinal direction (the same as the longitudinal direction of the half-wave plate 11).
  • the width and interval of the half-wave plate 11 and the size (height, length, and width) of the anisotropic refracting portion 13 are appropriately set in consideration of light guide conditions and emission conditions.
  • the height is a thickness in a direction perpendicular to the emission surface 10a on the side where the half-wave plate 11 of the light guide 10 is provided.
  • the length and width are the lengths of two intersecting sides when the anisotropic refracting portion 13 is viewed from a direction perpendicular to the emission surface 10a.
  • a part of light (non-polarized light) incident on the first end surface of the light guide 10 from the light source is reflected between the emission surface 10a and the reflective layer 12 and guided.
  • the light propagates in the light body 10 toward the second end face facing the first end face. In this propagation process, a part of the light enters the anisotropic refracting portion 13.
  • the anisotropic refracting unit 13 includes first and second emission conditions between the emission surface 10a and the reflective layer 12 and emission conditions for emitting the first and second polarized lights from different regions of the emission surface 10a.
  • the light guide condition for guiding the polarized light is satisfied.
  • FIG. 3 is a diagram for explaining the emission conditions of the anisotropic refracting unit 13 with respect to the first and second polarized lights.
  • a part of the polarization light guide plate shown in FIG. It is the schematic diagram of the cross section cut
  • an arrow indicated by a solid line indicates P-polarized light
  • an arrow indicated by a broken line indicates S-polarized light.
  • the refractive index for P-polarized light is n1
  • the refractive index for S-polarized light is n2.
  • the S-polarized light incident at an angle ⁇ 0 formed with the surface 13a with respect to the surface 13a located on the light exit surface 10a side of the light guide 10 is refracted at an angle ⁇ 1 and is surface 13a. It reaches the surface 13b opposite to.
  • the incident angle of the S-polarized light with respect to the surface 13a is given by “90 ° ⁇ 0”, which is larger than the angle ⁇ 1.
  • the surface 13b is an interface between the anisotropic refracting portion 13 and the reflective layer 12.
  • the S-polarized light incident from the surface 13a and reaching the surface 13b is reflected by the surface 13b.
  • the S-polarized light reflected by the surface 13b reaches the side surface 13c.
  • the refractive index of the half-wave plate 11 is substantially equal to the refractive index of the light guide 10, the S-polarized light from the side surface 13 c passes through the surface 10 a without being refracted and passes through the half-wave plate 11. Incident in. In the half-wave plate 11, the incident light reaches the surface 11 a opposite to the light guide 10. When the incident angle (90 ° ⁇ 1) of the incident light with respect to the surface 11a is smaller than the critical angle, the incident light is emitted from the surface 11a at the emission angle ⁇ . The light emitted from the surface 11a is P-polarized light.
  • S-polarized light that satisfies the condition of being incident from the surface 13 a and emitted from the side surface 13 c is P-polarized light by the half-wave plate 11. After being converted to, the light is emitted at an emission angle ⁇ .
  • the S-polarized light incident from the surface 13 a and emitted from the side surface 13 c is reflected by the reflective layer 12 and then passes through the half-wave plate 11.
  • the condition of emission is also established as the emission condition.
  • the P-polarized light incident at the incident angle ⁇ 0 with respect to the side surface 13d located on the first end surface side of the light guide 10 is refracted at the angle ⁇ 1 (> ⁇ 0). , Reach the surface 13b.
  • the P-polarized light incident from the side surface 13d and reaching the surface 13b is reflected by the surface 13b.
  • the P-polarized light reflected by the surface 13b reaches the surface 13a.
  • the incident angle (90 ° ⁇ 1) of the P-polarized light from the surface 13a with respect to the emission surface 10a is smaller than the critical angle, the P-polarized light is emitted from the emission surface 10a at the emission angle ⁇ .
  • the P-polarized light that satisfies the condition (exit condition) that is incident from the side surface 13d and emitted from the surface 13a is emitted from the output surface 10a at the output angle ⁇ .
  • the condition that the P-polarized light incident from the side surface 13d is directly emitted from the surface 13a without passing through the reflective layer 12 is also satisfied as the emission condition.
  • the region where the S-polarized light is emitted from the exit surface 10a is the P-polarized light of the exit surface 10a. It is different from the region where light is emitted.
  • the half-wave plate 11 is formed on a region of the emission surface 10a where S-polarized light is emitted.
  • the half-wave plate 11 may be formed not on the area of the emission surface 10a where S-polarized light is emitted but on the area where P-polarized light is emitted. In this case, light emitted from the polarization light guide plate is S-polarized light.
  • FIG. 4 is a diagram for explaining the light guide conditions of the anisotropic refracting portion 13, and a part of the polarization light guide plate shown in FIG. 1 is replaced with the first end face of the light guide 10 and the exit face 10 a. It is a schematic diagram of the cross section cut
  • the S-polarized light incident on the surface 13a at an angle ⁇ 0 ′ formed with the surface 13a is refracted at an angle ⁇ 1 ′ and reaches the surface 13b.
  • the S-polarized light incident from the surface 13a and reaching the surface 13b is reflected by the surface 13b.
  • the S-polarized light reflected by the surface 13b reaches the side surface 13c.
  • the angle between the S-polarized light emitted from the side surface 13c and the side surface 13c is ⁇ 1 '.
  • the incident angle (90 ° ⁇ 1 ′) of the S-polarized light from the side surface 13c with respect to the emission surface 10a is larger than the critical angle. Therefore, the S-polarized light is reflected by the emission surface 10a.
  • the S-polarized light that satisfies the light guide condition of entering from the surface 13a, reflected by the surface 13b, and emitted from the side surface 13c is reflected by the exit surface 10a. And propagates in the light guide 10.
  • the P-polarized light incident at the incident angle ⁇ 0 ′ on the side surface 13d is refracted at the angle ⁇ 1 ′ and reaches the surface 13b.
  • the P-polarized light incident from the side surface 13d and reaching the surface 13b is reflected by the surface 13b.
  • the P-polarized light reflected by the surface 13b reaches the surface 13a.
  • the incident angle ⁇ 2 ′ of the P-polarized light reflected by the surface 13b with respect to the surface 13a is smaller than the critical angle. For this reason, the P-polarized light incident on the surface 13 a from the surface 13 b is refracted and reaches the output surface 10 a of the light guide 10.
  • the angle between the P-polarized light emitted from the surface 13a and the surface 13a is ⁇ 1 ′.
  • the incident angle (90 ° ⁇ 1 ′) of the P-polarized light from the surface 13a with respect to the emission surface 10a is larger than the critical angle. Therefore, the P-polarized light is reflected by the exit surface 10 a and propagates through the light guide 10.
  • the P-polarized light that satisfies the light guide condition of entering from the side surface 13d, reflected by the surface 13b, and emitted from the surface 13a is reflected by the emission surface 10a. And propagates in the light guide 10.
  • FIG. 5 is a diagram for explaining another light guide condition of the anisotropic refracting portion 13, and a part of the polarization light guide plate shown in FIG. It is a schematic diagram of the cross section cut
  • the S-polarized light incident at the incident angle ⁇ 0 ′ on the side surface 13d is refracted at the angle ⁇ 1 ′ and reaches the surface 13b.
  • S-polarized light incident from the side surface 13d and reaching the surface 13b is reflected by the surface 13b.
  • the S-polarized light reflected by the surface 13b reaches the surface 13a.
  • the angle between the S-polarized light emitted from the surface 13a and the surface 13a is ⁇ 1 '.
  • the incident angle (90 ° ⁇ 1 ′) of the S-polarized light from the surface 13a with respect to the emission surface 10a is larger than the critical angle. Therefore, the S-polarized light is reflected by the emission surface 10 a and propagates through the light guide 10.
  • the S-polarized light that satisfies the light guide condition of entering from the side surface 13d, reflected by the surface 13b, and emitted from the surface 13a is reflected by the emission surface 10a. And propagates in the light guide 10.
  • the P-polarized light incident on the surface 13a at an angle ⁇ 0 ′ formed with the surface 13a is refracted at an angle ⁇ 1 ′ and reaches the surface 13b.
  • the P-polarized light incident from the surface 13a and reaching the surface 13b is reflected by the surface 13b.
  • the P-polarized light reflected by the surface 13b is incident on the side surface 13c at an incident angle ⁇ 2 ′.
  • the incident angle ⁇ 2 ′ is smaller than the critical angle. Therefore, the P-polarized light incident on the side surface 13c from the surface 13b is refracted at an angle ⁇ 1 'and reaches the output surface 10a.
  • the incident angle (90 ° - ⁇ 1 ') of the P-polarized light incident on the exit surface 10a is larger than the critical angle. Therefore, the P-polarized light is reflected by the emission surface 10 a and propagates through the light guide 10.
  • the P-polarized light that satisfies the light guide condition of entering from the surface 13a, reflected by the surface 13b, and emitted from the side surface 13c is reflected by the emission surface 11a. And propagates in the light guide 10.
  • the first and second polarized lights (S-polarized light and P-polarized light) satisfying the emission condition of the anisotropic refracting unit 13 are emitted from the emission surface 10a. Emitted.
  • One of the first and second polarized light emitted from the emission surface 10 a is polarized and converted by the half-wave plate 11.
  • the spread of the emission angle is controlled within a range that the angle ⁇ can take.
  • the emission angle ⁇ is taken in the in-plane direction of the first plane intersecting (or orthogonal to) each of the first end face (end face on the side where the light source is disposed) of the light guide 10 and the emission face 11a. The output angle to obtain.
  • the emission angle ⁇ is 67.3 °. is there.
  • the emission angle ⁇ is 80.5 °.
  • the emission angle ⁇ is 89.8 °.
  • the emission angle width is 22.5 °.
  • the emission angle width is an angle width given by the maximum angle and the minimum angle of the emission angle ⁇ , and is an angular spread of the emission angle of the outgoing light of the polarizing light guide plate of the present embodiment.
  • the magnitude relationship between the refractive indexes of S-polarized light and P-polarized light and the region where the half-wave plate 11 is formed can be changed as appropriate.
  • the first polarized light on the emission surface 10a of the light guide 10 is used.
  • the first region from which the light is emitted and the second region from which the second polarized light is emitted need to be completely separated.
  • the size and interval of the anisotropic refracting portion 13 capable of separating the region where the first and second polarized lights are emitted from the emission surface 10a will be described.
  • FIG. 6 is a diagram for explaining the size conditions (thickness and width) of the anisotropic refracting portion 13 and is cut along a plane perpendicular to the first end face of the light guide 10 and the exit face 10a.
  • the arrow indicated by a broken line is S-polarized light
  • the arrow indicated by a solid line is P-polarized light.
  • the width of the anisotropic refracting portion 13 (the length of the surfaces 13a and 13b) is B
  • the thickness of the anisotropic refracting portion 13 is H
  • the thickness of the light guide 10 is as follows. Is D.
  • the maximum angle of the P-polarized light incident from the surface 13a and emitted from the side surface 13c with the perpendicular of the side surface 13c is ⁇ 1max, and the maximum angle ⁇ 1max is given to the P-polarized light incident on the surface 13a.
  • An angle formed with the surface 13a is set to ⁇ 0max.
  • the minimum angle of the S-polarized light incident from the side surface 13d and emitted from the surface 13a with the surface 13a is ⁇ 1min
  • the side surface 13d of the S-polarized light incident on the side surface 13d is given the minimum angle ⁇ 1min.
  • the angle formed by the perpendicular to is ⁇ 0 min.
  • X be the shortest distance from the exit point of the S-polarized light emitted at the minimum angle ⁇ 1 min on the surface 13a to the end of the surface 13a on the side surface 13c side.
  • a region where the first and second polarized lights are emitted from the exit surface 10a (the exit region of S-polarized light and P-polarized light emission area) can be separated.
  • FIG. 7 is a diagram for explaining the interval between the anisotropic refracting portions, and is a schematic diagram of a cross section cut along a plane perpendicular to the first end face of the light guide 10 and the emission face 10a.
  • the arrow indicated by a broken line is S-polarized light
  • the arrow indicated by a solid line is P-polarized light.
  • the interval between two adjacent anisotropic refracting portions 13A and 13B is P.
  • the anisotropic refracting portion 13 ⁇ / b> A is disposed on the first end surface (end surface on the side where the light source is provided) side of the light guide 10.
  • a region where the first and second polarized lights are emitted from the emission surface 10a (emission of S-polarized light) Region and the exit region of P-polarized light) can be separated.
  • the distance between the anisotropic refracting portions 13 is narrowed so that the light is reflected by the reflective layer 12 and enters from the side surface 13d of the anisotropic refracting portion 13 and exits from the surface 13a.
  • the first polarized light and the second polarized light that is incident from the surface 13a of the anisotropic refracting portion 13 and is emitted from the side surface 13c are not emitted from the emission surface 10a, but are guided through the light guide 10. It can also be configured to shine.
  • FIG. 8 is a diagram for explaining the interval between the anisotropic refracting portions, and is a schematic diagram of a cross section cut along a plane perpendicular to the first end face of the light guide 10 and the emission face 10a.
  • the arrow indicated by a broken line is S-polarized light
  • the arrow indicated by a solid line is P-polarized light.
  • the interval between two adjacent anisotropic refracting portions 13A and 13B is P.
  • the anisotropic refracting portion 13 ⁇ / b> A is disposed on the first end surface (end surface on the side where the light source is provided) side of the light guide 10.
  • the width (length of the surfaces 13a and 13b) of each of the anisotropic refracting portions 13A and 13B is B, and the thickness (the length of the side surfaces 13c and 13d) is H.
  • D be the thickness of the light guide 10.
  • the maximum angle of the S-polarized light incident on the reflective layer 12 without passing through the anisotropic refracting portion 13A and the reflective layer 12 is ⁇ 0max.
  • the maximum angle of the S-polarized light incident from the side surface 13d and emitted from the surface 13a with the surface 13a is ⁇ 1max.
  • the light is reflected by the reflective layer 12 and is incident from the side surface 13d of the anisotropic refracting portion 13B.
  • the S-polarized light emitted from the surface 13a and the P-polarized light incident from the surface 13a of the anisotropic refracting portion 13A, reflected by the surface 13b, and emitted from the side surface 13c can be guided.
  • FIG. 9 is a schematic diagram for explaining the configuration of the polarizing light guide plate according to the first embodiment of the present invention.
  • the arrow indicated by a broken line is S-polarized light
  • the arrow indicated by a solid line is P-polarized light.
  • the width of the anisotropic refracting portion 13 is B, and the thickness is H.
  • D be the thickness of the light guide 10.
  • the width of the half-wave plate 11 is b.
  • P-polarized light from the anisotropic refracting portion 13 that enters the half-wave plate 11 directly or through the reflective layer 12 enters the P-polarized light that enters from the surface on the exit surface 10a side and exits from the side surface.
  • L be the shortest distance between the plane including the emitted side surface and the end of the half-wave plate 11.
  • P be the distance between the anisotropic refracting portions 13.
  • the interval P between the anisotropic refracting portions 13 satisfies the conditions of the above-described formulas (1) to (6).
  • the refractive index n0 of the light guide 10 is 1.50, and the refractive indexes n1 and n2 of the anisotropic refracting portion 13 are 1.45 and 1.55, respectively.
  • the thickness D of the light guide 10 is 1 mm.
  • the anisotropic refractive portion 13 has a width B of 300 ⁇ m and a thickness H of 100 ⁇ m.
  • the spacing P between the anisotropic refracting portions 13 is 300 ⁇ m.
  • the width b of the half-wave plate 11 is 285 ⁇ m.
  • the shortest distance L is 701 ⁇ m.
  • the emission angle ⁇ is 67.3 °.
  • the emission angle ⁇ is 80.5 °.
  • the emission angle ⁇ is 89.8 °.
  • the maximum angle of the light incident on the light guide 10 from the light source with respect to the plane parallel to the output surface 10a is 48.1 ° or less, the angular spread of the output angle of the output light of the polarizing light guide plate is 22.7 °. Can be about.
  • FIG. 10 is a schematic diagram for explaining a configuration of a polarizing light guide plate according to the second embodiment of the present invention.
  • an arrow indicated by a broken line is S-polarized light
  • an arrow indicated by a solid line is P-polarized light.
  • the width of the anisotropic refracting portion 13 is B, and the thickness is H.
  • D be the thickness of the light guide 10.
  • the width of the half-wave plate 11 is b.
  • P-polarized light from the anisotropic refracting portion 13 that enters the half-wave plate 11 directly or through the reflective layer 12 enters the P-polarized light that enters from the surface on the exit surface 10a side and exits from the side surface.
  • L be the shortest distance between the plane including the emitted side surface and the end of the half-wave plate 11.
  • P be the distance between the anisotropic refracting portions 13.
  • the interval P between the anisotropic refracting portions 13 satisfies the conditions of the expressions (7) to (8) described above.
  • the refractive index n0 of the light guide 10 is 1.50, and the refractive indexes n1 and n2 of the anisotropic refracting portion 13 are 1.45 and 1.55, respectively.
  • the thickness D of the light guide 10 is 1 mm.
  • the anisotropic refractive portion 13 has a width B of 300 ⁇ m and a thickness H of 100 ⁇ m.
  • the spacing P between the anisotropic refracting portions 13 is 80 ⁇ m.
  • the width b of the half-wave plate 11 is 196 ⁇ m.
  • the shortest distance L is 701 ⁇ m.
  • the emission angle ⁇ is 67.3 °.
  • the emission angle ⁇ is 80.5 °.
  • the emission angle ⁇ is 89.8 °.
  • the maximum angle of the light incident on the light guide 10 from the light source with respect to the plane parallel to the output surface 10a is 48.1 ° or less, the angular spread of the output angle of the output light of the polarizing light guide plate is 22.7 °. Can be about.
  • Example 3 The polarizing light guide plate of the third embodiment of the present invention is also configured as shown in FIG.
  • the refractive index n0 of the light guide 10 is 1.50
  • the refractive indexes n1 and n2 of the anisotropic refracting portion 13 are 1.45 and 1.55, respectively.
  • the light guide 10 has a thickness D of 500 ⁇ m.
  • the anisotropic refracting portion 13 has a width B of 260 ⁇ m and a thickness H of 100 ⁇ m.
  • the spacing P between the anisotropic refracting portions 13 is 80 ⁇ m.
  • the width b of the half-wave plate 11 is 50 ⁇ m.
  • the shortest distance L is 310 ⁇ m.
  • the emission angle ⁇ is 67.3 °.
  • the emission angle ⁇ is 80.5 °.
  • the emission angle ⁇ is 89.8 °.
  • the angular spread of the outgoing angle of the outgoing light from the polarizing light guide plate can be set to about 22.7 °.
  • the polarization light guide plate of the present embodiment described above it is possible to keep the spread of the emission angle of light emitted from the polarization light guide plate within a light usable range based on etendue restrictions.
  • the light propagating in the light guide 10 can be used by circulating light between the quarter-wave plate 11 and the reflection layer 12, the light use efficiency can be improved.
  • angle conversion means is provided in order to effectively use incident light having a certain degree of emission angle distribution from a light source.
  • the angle conversion means include a method of making the light guide plate a wedge shape, a method of providing a prism portion in the light guide plate, and the like.
  • the light guide plate used in the projector illumination device is small, for example, if the wedge angle of the wedge-shaped structure (angle formed by the reflecting surface and the exit surface) is small, the incident light reaches the surface facing the entrance surface. By this time, a sufficient change in the light guide angle cannot be obtained, and the effect of increasing the amount of light by the wedge-shaped structure is halved. For this reason, the wedge-shaped structure has a wedge angle that is somewhat large.
  • the angle conversion means is realized by, for example, a configuration in which the thickness of the first layer is gradually reduced as the distance from the incident surface increases.
  • the P-polarized light that satisfies the angle condition and is reflected by the prism surface of the second layer passes through the first layer and the polarization conversion plate and is reflected in the direction of the first layer by the reflecting plate. At this time, the P-polarized light is converted into S-polarized light by the polarization conversion plate, and the light guide angle is changed by the wedge-shaped structure. In this case, if the wedge angle is small to some extent, the S-polarized light reflected by the reflecting plate is emitted from the exit surface of the light guide plate in order to satisfy the angle condition.
  • the polarizing light guide plate of the present embodiment the light satisfying the angle condition (emission condition) is emitted from the emission surface 10a of the light guide 10 regardless of the polarization state. Further, since the light guide angle of the incident light is changed by passing through the anisotropic refracting portion 13, it is not necessary to use an angle conversion means such as a wedge structure. Therefore, according to the polarizing light guide plate of the present embodiment, it is possible to realize a projector having a large amount of emitted light and a high brightness as compared with the light guide plate described in Patent Document 1.
  • a light guide having a concave portion in a region to be the anisotropic refracting portion 13 is created.
  • the light guide can be created for mold forming, cutting and the like.
  • an alignment film is applied to the surface of the light guide where the concave portion is formed and one surface of the reflective layer (reflecting plate), and an alignment treatment is performed.
  • a UV curable liquid crystal monomer is embedded in the recess by screen printing. Thereafter, the surface of the light guide body on which the concave portion is formed and one surface of the reflective layer are bonded together.
  • the bonded light guide and reflective layer are heated and then cooled to align the UV curable liquid crystal monomer. Finally, UV light is irradiated to cure the aligned UV curable liquid crystal monomer, and then a half-wave plate is attached to a predetermined region on the surface of the light guide opposite to the reflective layer. Thereby, the polarization light guide plate of the first embodiment is obtained.
  • the outgoing light has an inclination with respect to the normal of the outgoing surface 10a.
  • a mode capable of emitting light in a direction perpendicular to the emission surface 10a will be described.
  • FIG. 11 is a cross-sectional view showing a configuration of a polarizing light guide plate according to the second embodiment of the present invention.
  • the polarizing light guide plate of this embodiment is obtained by adding a prism sheet 15 to the polarizing light guide plate of the first embodiment.
  • the configuration other than the prism sheet 15 is the same as that of the polarizing light guide plate of the first embodiment.
  • the plurality of apex angles of the prism sheet 15 are provided so as to face the light exit surface 10 a of the light guide 10.
  • FIG. 12 shows an enlarged view in which a part of the prism sheet 15 is enlarged.
  • the prism sheet 15 is formed by two-dimensionally arranging prism surfaces 15a having a triangular cross-sectional shape.
  • the apex angle of the prism surface 15a is determined based on the angle of light emitted from the emission surface 10a and the half-wave plate 11 (for example, the emission angle ⁇ shown in FIG. 3). For example, when the emission angle ⁇ is larger than 67 ° and smaller than 90 °, assuming that the refractive index of the prism sheet 15 is 1.50, the apex angle of the prism surface 15a is about 70 °.
  • the prism sheet 15 having the prism surface 15a having an apex angle of 70 ° has an angle ⁇ formed by a surface parallel to a surface forming one side of the triangular shape of the prism surface 15a and the emission surface 10a, so that 55 °. It arrange
  • the half-wave plate 11 is a first quarter-wave plate, and a second quarter-wave plate is interposed between the first quarter-wave plates. May be provided.
  • the first and second quarter-wave plates are alternately and periodically arranged in a fixed direction (the direction in which the anisotropic refracting portions 13 are arranged).
  • the optical axis of the first quarter-wave plate is orthogonal to the optical axis of the second quarter-wave plate.
  • the S-polarized light passes through the first quarter-wave plate, and the P-polarized light.
  • Light passes through the second quarter-wave plate.
  • circularly polarized light in the same rotational direction (clockwise or counterclockwise circularly polarized light) is emitted from each of the first and second quarter wavelength plates.
  • the polarizing light guide plate of the other embodiment also satisfies the conditions for the emission condition, the light guide condition, the size of the anisotropic refracting portion 13 (thickness and width), and the interval described in the first embodiment. .
  • FIG. 13 shows an example of a cross-sectional structure of an illuminating device provided with the polarizing light guide plate of the present invention.
  • the illumination device shown in FIG. 13 includes the polarization light guide plate shown in FIG. This illuminating device can be used as an illuminating device for a liquid crystal display device such as a mobile phone or a projection display device represented by a liquid crystal projector.
  • the light source 20 is, for example, a semiconductor light source such as a light emitting diode (LED) or a semiconductor laser (LD), or a light source called a solid light source, and is provided so as to face the end face 10 b of the light guide 10.
  • the light source 20 may be arranged in any manner with respect to the end face 10b.
  • the light emitting unit of the light source 20 may be disposed close to the end surface 10b, and an optical member (prism or lens) for causing light from the light emitting unit to enter the end surface 10b between the light emitting unit and the end surface 10b. ) May be arranged.
  • the light (unpolarized light) emitted from the light source 20 enters the light guide 10 from the end face 10b.
  • Light (non-polarized light) incident on the end surface 10b of the light guide body 10 from the light source 20 is reflected by the exit surface 10a and the reflective layer 12, and in the light guide body 10 toward the end surface 10c facing the end surface 10b. Propagate toward. In this propagation process, a part of the light enters the anisotropic refracting portion 13.
  • the first and second polarized light satisfying the emission condition are emitted from the emission surface 10a.
  • the region where the first polarized light is emitted is different from the region where the second polarized light is emitted.
  • the half-wave plate 11 is provided in a region where the first polarized light is emitted, and the first polarized light emitted from the emission surface 10 a is converted into the second polarized light by the half-wave plate 11. Converted.
  • the half-wave plate 11 is provided in a region where S-polarized light is emitted, and the S-polarized light emitted from the emission surface 10 a is converted into P-polarized light by the half-wave plate 11. Is converted to
  • the angular spread (outgoing angle) of the outgoing light by the anisotropic refracting unit 13 can be kept within the usable range of light based on etendue restrictions.
  • the polarization light guide plate of 1st Embodiment may replace with this and the polarization light guide plate of 2nd Embodiment or the polarization light guide plate of other embodiment may be used. .
  • the some light source 20 may be provided with respect to the end surface 10b.
  • At least one light source 20 may be provided on both of the end faces 10b and 10c.
  • the illumination device including the polarization light guide plate of the present invention described above can be applied to a projection display device typified by a liquid crystal projector.
  • FIG. 14 is a schematic diagram showing a configuration of a projection display device using an illumination device including the polarization light guide plate of the present invention.
  • the projection display device includes illumination devices 300 to 302, liquid crystal elements 303 to 305 as display elements, a cross dichroic mirror 306, and a projection optical system 307.
  • All of the lighting devices 300 to 302 are constituted by the lighting devices described above.
  • a blue LED is used as the light source of the illumination device 300.
  • a green LED is used as the light source of the illumination device 301.
  • a red LED is used as the light source of the illumination device 302.
  • the blue light emitted from the illumination device 300 is applied to the liquid crystal element 303.
  • the liquid crystal element 303 is driven by a liquid crystal driving circuit (not shown) and forms a blue image based on a video signal supplied from the outside.
  • the green light emitted from the illumination device 301 is applied to the liquid crystal element 304.
  • the liquid crystal element 304 is driven by a liquid crystal driving circuit (not shown) and forms a green image based on a video signal supplied from the outside.
  • the red light emitted from the illumination device 302 is applied to the liquid crystal element 305.
  • the liquid crystal element 305 is driven by a liquid crystal drive circuit (not shown), and forms a red image based on a video signal supplied from the outside.
  • the image light of each color formed by the liquid crystal elements 303 to 305 enters the projection optical system 307 via the cross dichroic mirror 306.
  • the projection optical system 307 projects each color image formed by the liquid crystal elements 303 to 305 onto a screen (or a member replacing the screen) (not shown).
  • Another projection type display device uses an illuminating device including light sources of red, green and blue colors on the end face of the polarizing light guide plate of the present invention.
  • light corresponding to white light
  • predetermined polarized light P-polarized light or S-polarized light
  • the display element displays red, green, and blue images based on an external video signal in a time division manner.
  • the light emission timing of the light source is controlled in synchronization with the time division display.
  • Each color image formed on the display element is projected by the projection optical system.
  • the polarizing light guide plate of the present invention and the illumination device including the same can be used as a backlight of a liquid crystal display in addition to the projection display device described above.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Nonlinear Science (AREA)
  • Mathematical Physics (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Planar Illumination Modules (AREA)
  • Light Guides In General And Applications Therefor (AREA)

Abstract

L'invention concerne une plaque de guidage de lumière polarisante qui comprend : un corps de guidage de lumière (10) qui présente des surfaces opposées dont l'une sert de surface d'émission (10a) ; une couche réfléchissante (12) réalisée sur l'autre surface des surfaces opposées du corps de guidage de lumière (10) ; une pluralité de plaques à demi-longueur d'onde (11) formées sur la surface d'émission (10a) du corps de guidage de lumière (10) à intervalles réguliers dans une certaine direction ; et une pluralité de parties de réfraction anisotropes (13) formées le long de l'autre surface à intervalles réguliers dans ladite direction à l'intérieur du corps de guidage de lumière (10). La partie de réfraction anisotrope (13) est réalisée de telle sorte qu'un indice de réfraction par rapport à une première lumière polarisée est inférieur à celui du corps de guidage de lumière (10) et un indice de réfraction par rapport à une deuxième lumière polarisée est supérieur à celui du corps de guidage de lumière (10).
PCT/JP2011/056761 2010-03-31 2011-03-22 Plaque de guidage de lumière polarisante, dispositif d'éclairage et dispositif d'affichage par projection WO2011125479A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2012509396A JPWO2011125479A1 (ja) 2010-03-31 2011-03-22 偏光導光板、照明装置および投射型表示装置

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2010-080792 2010-03-31
JP2010080792 2010-03-31

Publications (1)

Publication Number Publication Date
WO2011125479A1 true WO2011125479A1 (fr) 2011-10-13

Family

ID=44762434

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2011/056761 WO2011125479A1 (fr) 2010-03-31 2011-03-22 Plaque de guidage de lumière polarisante, dispositif d'éclairage et dispositif d'affichage par projection

Country Status (2)

Country Link
JP (1) JPWO2011125479A1 (fr)
WO (1) WO2011125479A1 (fr)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH1078511A (ja) * 1996-09-04 1998-03-24 Hitachi Ltd 偏光分離器、偏光変換素子およびそれを用いた液晶表示装置
JPH10125121A (ja) * 1996-10-22 1998-05-15 Matsushita Electric Ind Co Ltd バックライト
JP2008235245A (ja) * 2007-02-19 2008-10-02 Mitsubishi Electric Corp バックライト装置および透過型表示装置

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH1078511A (ja) * 1996-09-04 1998-03-24 Hitachi Ltd 偏光分離器、偏光変換素子およびそれを用いた液晶表示装置
JPH10125121A (ja) * 1996-10-22 1998-05-15 Matsushita Electric Ind Co Ltd バックライト
JP2008235245A (ja) * 2007-02-19 2008-10-02 Mitsubishi Electric Corp バックライト装置および透過型表示装置

Also Published As

Publication number Publication date
JPWO2011125479A1 (ja) 2013-07-08

Similar Documents

Publication Publication Date Title
KR101706246B1 (ko) 디스플레이 모듈 및 광 가이드 디바이스
EP3021162B1 (fr) Appareil d'affichage de projection
JP5424365B2 (ja) 照明装置とそれを用いた投射型表示装置
US20220317467A1 (en) Optical Devices Having Dichroic Beam Combiners, Optical Devices for Use with Dichroic Beam Combiners, and Methods of Manufacture Therefor
KR101747286B1 (ko) 디스플레이 모듈
KR101976991B1 (ko) 웨어러블 디스플레이 장치
JP6081508B2 (ja) 直線配置型の接眼映像表示装置
JP5153535B2 (ja) 画像投射装置
TW201833653A (zh) 投影系統
JP2016213175A5 (fr)
JP2010101989A (ja) ディスプレイ装置
WO2011021304A1 (fr) Dispositif d'éclairage et dispositif d'affichage par projection l'utilisant
JP5741445B2 (ja) 照明装置およびそれを用いた投射型表示装置
WO2011125479A1 (fr) Plaque de guidage de lumière polarisante, dispositif d'éclairage et dispositif d'affichage par projection
JP2009229729A (ja) 偏光素子、およびプロジェクタ
US8807769B2 (en) Wavelength plate, light emitting element, and image display device using the light emitting element
WO2011118563A1 (fr) Plaque de guidage de lumière à déviation, appareil d'éclairage et appareil d'affichage du type projection
JP2008112623A (ja) 光源装置、プロジェクタ
TWI556025B (zh) 顯示模組和導光裝置
US11454875B2 (en) Prism architecture
JP4910354B2 (ja) 均一化光学素子、照明装置及びプロジェクタ
JP2010067552A (ja) バックライト装置および液晶ディスプレイ装置
JP2009122218A (ja) 照明装置及び画像表示装置

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 11765380

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 2012509396

Country of ref document: JP

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 11765380

Country of ref document: EP

Kind code of ref document: A1