JP2018112658A - Screen, light for illumination selection device, and lighting instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a screen, a light for illumination selection device, and a lighting instrument that can reduce reflection of external light and project a clear video.SOLUTION: A screen comprises: a waveguide layer that has, on its surface, a plurality of types of reflecting areas that each have a rugged structure and reflect light in a predetermined wavelength region; and a clad layer that has a lower refractive index than the refractive index of a material of the waveguide layer. In particular, the screen 100 is formed of the waveguide layer 1 that has, on its surface, a blue reflecting area B that has a first rugged structure and reflects blue light in a predetermined wavelength region, a green reflecting area G that has a second rugged structure and reflects green light in a predetermined wavelength region, and a red reflecting area R that has a third rugged structure and reflects red light in a predetermined wavelength region; and the clad layer 2 that has a lower refractive index than the refractive index of the material of the waveguide layer 1.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a screen for projecting an image by a projection device, an illumination light selection device used for illumination of a space in which the screen is arranged, and a lighting fixture.

  2. Description of the Related Art Conventionally, there is a screen for displaying an image by projecting light emitted from a projection device such as a projector. The screen displays an image by reflecting light on the surface. However, when there is external light such as natural light or illumination, the external light is reflected by the screen and reaches the observer. Then, the observer observes the image by the projection unit and the external light at the same time, which causes a decrease in the contrast of the image. In order to reduce such a decrease in image contrast, the projection light from the projection optical system of the projector is projected, and the projection light incident in a predetermined angle range determined according to the F value of the projection optical system is scattered. And a screen having a light scattering layer having an angle characteristic that transmits light that is different from the projection light and that is incident in an angle range other than a predetermined angle range has been proposed (for example, patents). Reference 1).

JP-A-2005-173235

  However, the reduction in contrast has not yet been sufficiently reduced. Therefore, an object of the present invention is to provide a screen, an illumination light selection device, and a lighting fixture that can suppress reflection of external light and display a clear image.

  In order to achieve the above object, the screen of the present invention includes a waveguide layer having a concavo-convex structure and a plurality of types of reflection regions on the surface that reflect light in a predetermined wavelength range, and a refractive index of the material of the waveguide layer. And a clad layer having a lower refractive index.

  In this case, a light absorption layer that absorbs light transmitted through the cladding layer may be provided. The light absorption layer is made of a material containing a light absorption component that absorbs light transmitted through the waveguide layer, and the average particle diameter of the light absorption component particles is less than half of the wavelength of light to be absorbed. Some are preferred.

  For example, the waveguide layer has a first uneven structure as a reflection region and reflects blue light in a predetermined wavelength range, and a second reflection structure and reflects green light in a predetermined wavelength range. A green reflective region and a red reflective region having a third uneven structure and reflecting red light in a predetermined wavelength region are provided on the surface.

  In this case, the first concavo-convex structure is a periodic structure having a resonating light wavelength peak between 400 and 490 nm, and the second concavo-convex structure has a resonating light wavelength peak between 495 and 570 nm. The third concavo-convex structure may be a periodic structure having a wavelength of resonating light between 610 and 750 nm.

  In order to widen the viewing angle, the shape of the convex portions of the first concavo-convex structure, the second concavo-convex structure, and the third concavo-convex structure may be a square or a circle. The first concavo-convex structure, the second concavo-convex structure, and the third concavo-convex structure may each be a double periodic grating. In addition, a diffusion plate may be provided between the blue reflection region, the green reflection region, and the red reflection region.

  In addition, it is preferable that the blue reflection region, the green reflection region, and the red reflection region have such a size that a unit region can be contained in a circle having a diameter of 300 μm.

  In addition, the illumination light selection device of the present invention includes a filter that suppresses transmission of blue light in a predetermined wavelength region, green light in a predetermined wavelength region, and red light in a predetermined wavelength region out of visible light. Features.

  In this case, the illumination light selection device is used for illumination for the space in which the screen of the present invention described above is arranged, and the filter has a blue wavelength in a predetermined wavelength range reflected by the screen. It is preferable to suppress transmission of light, green light in a predetermined wavelength range, and red light in a predetermined wavelength range.

  Moreover, it is more preferable to provide the attachment / detachment means for attaching / detaching to a lighting fixture.

  Moreover, the luminaire of the present invention comprises a light emitting element that emits light other than blue light in a predetermined wavelength range, green light in a predetermined wavelength range, and red light in a predetermined wavelength range among visible light. To do.

  In this case, the luminaire is used for illumination for a space in which the screen of the present invention is disposed, and the light emitting element is blue light having a predetermined wavelength range reflected by the screen, a predetermined wavelength. It is preferable to emit light other than the green light in the range and the red light in the predetermined wavelength range.

  The screen of the present invention reflects the light of the projection device and suppresses the reflection of other light, so that a clear image can be projected. Moreover, since the illumination light selection device and the lighting fixture of the present invention can suppress the light reflected by the screen of the present invention, a clearer image can be projected on the screen.

It is a schematic perspective view for demonstrating the screen of this invention. It is a schematic perspective view which shows the uneven structure of the reflective area | region of this invention. It is a schematic explanatory drawing at the time of utilizing the screen of this invention for a head-up display. It is a schematic perspective view for demonstrating another screen of this invention. It is a schematic perspective view which shows the uneven structure of another reflective area | region of this invention. It is a figure for demonstrating the usage condition of the screen of this invention. It is a graph which shows the optical characteristic by the difference in the pitch of the uneven structure which concerns on this invention. It is a schematic sectional drawing which shows the scattering plate which concerns on this invention. It is a schematic sectional drawing which shows another scattering plate which concerns on this invention. It is a schematic perspective view which shows another uneven structure which concerns on this invention. It is a graph which shows the optical characteristic by another uneven structure which concerns on this invention. It is a graph which shows the optical characteristic by another uneven structure which concerns on this invention. It is explanatory drawing which shows the Fourier component of the uneven structure and refractive index modulation which concern on this invention.

  The screen of the present invention will be described below. The screen of the present invention is mainly composed of a waveguiding layer and a cladding layer.

  The waveguiding layer has a concavo-convex structure and a plurality of types of reflecting regions on the surface that reflect light in a predetermined wavelength range. The concavo-convex structure may be anything as long as the peak of the wavelength of the resonating light is within a desired predetermined wavelength range. For example, if the concavo-convex structure is a line and space and the pitch P is adjusted, the peak wavelength of reflected light can be adjusted to a predetermined wavelength range. Note that the shape, pitch, and the like of the concavo-convex structure may be calculated and determined using a tool capable of simulation such as the RCWA method and the FDTD method.

  Here, the plurality of types of reflection regions mean regions having different uneven structures and different wavelength ranges of reflected light. For example, the waveguide layer 1 of the screen 100 shown in FIG. 1 includes a blue reflection region B that reflects blue light in a predetermined wavelength region, a green reflection region G that reflects green light in a predetermined wavelength region, and a predetermined wavelength region. The surface has three types of reflection regions, a red reflection region R that reflects red light.

The blue reflection region B has a first concavo-convex structure 11 for reflecting blue light in a predetermined wavelength region. The contrast of the image projected on the screen 100 can be improved by matching the reflected light with the light emitted by the projection unit that projects the light onto the screen. The first concavo-convex structure 11 may be anything as long as the peak of the wavelength of the resonating light is between 435 and 490 nm. For example, it is possible to the first concavo-convex structure 11 and a line-and-space, by adjusting the pitch P _1, to adjust the peak wavelength of the reflected light during 400～490Nm. In addition, it is better that the blue reflection region B reflects only blue light in a predetermined wavelength region in visible light.

As shown in FIG. 2B, the green reflective region G has a second concavo-convex structure 12 for reflecting green light in a predetermined wavelength range. The contrast of the image projected on the screen 100 can be improved by matching the reflected light with the light emitted by the projection unit that projects the light onto the screen. The second concavo-convex structure 12 may be any structure as long as the wavelength peak of the resonating light is between 495 and 570 nm. For example, it is possible to the second concave-convex structure 12 and a line-and-space, by adjusting the pitch P _2, to adjust the peak wavelength of the reflected light during 495～570Nm. In addition, the green reflection area | region G should reflect only the green light of a predetermined wavelength range among visible lights.

As shown in FIG. 2 (3), the red reflection region R has a third uneven structure 13 for reflecting red light in a predetermined wavelength region. The contrast of the image projected on the screen 100 can be improved by matching the reflected light with the light emitted by the projection unit that projects the light onto the screen. The third concavo-convex structure 13 may be anything as long as the peak of the wavelength of the resonating light is between 620 and 750 nm. For example, it is possible to a third concave-convex structure 13 and a line-and-space, by adjusting the pitch P _3, to adjust the peak wavelength of the reflected light during 620～750Nm. In addition, it is better for the red reflection region R to reflect only red light in a predetermined wavelength region in visible light.

  The wavelength range of the light reflected by the blue reflection region B, the green reflection region G, and the red reflection region R is designed according to the wavelength range of the blue light, green light, and red light of the projection unit that projects an image on the screen. preferable.

  In addition, the reflective area | region in the screen of this invention is not restricted to what reflects blue, green, and red light, You may design so that the light of colors other than these may reflect. In addition, the wavelength range of the reflected light is not limited to visible light, and can be designed in a wavelength range such as ultraviolet or infrared.

  The clad layer 2 is provided on the back side of the waveguide layer and is made of a material having a refractive index lower than that of the material of the waveguide layer 1. Thereby, the clad layer 2 plays a role of confining light in the waveguide layer 1 having a high refractive index.

  The screen 100 configured as described above can be used as a head-up display (screen 100) of an automobile 8 including a head-up display projection device 91 as shown in FIG. 3, for example. Specifically, of the visible light, the blue reflection region B having the first uneven structure 11 that reflects only the blue light irradiated by the head-up display projection device 91, and the second uneven structure that reflects only the green light. The screen 100 may be constituted by the waveguide layer 1 and the clad layer 2 having the green reflective region G having 12 and the red reflective region R having the third uneven structure 13 that reflects only red light. The windshield glass 101 itself can be used as the screen 100.

  Further, another screen 200 of the present invention further includes a light absorption layer 3 that absorbs light transmitted through the blue reflection region B, the green reflection region G, and the red reflection region R, as shown in FIGS. May be.

  The light absorption layer 3 may be any material as long as it absorbs light transmitted through at least the cladding layer 2. Here, the material that absorbs light refers to a material that absorbs light more than at least reflects light. Preferably, the extinction coefficient k is 0.4 or less, preferably 0.2 or less. More preferably, it is 0.1 or less. The material may contain a light absorbing component that easily absorbs light in a resin or the like. Examples of the light absorbing component include black pigments such as carbon black, aniline black, titanium black, and acetylene black.

  Moreover, it is preferable that the particle diameter of the light absorption component is sufficiently small with respect to the wavelength of light to be absorbed so that scattering and reflection do not occur. Specifically, the average particle diameter of the particles contained in the material should be less than or equal to one-half of the wavelength of light to be absorbed, more preferably less than or equal to one-fourth. In addition, what is necessary is just to measure the average particle diameter of a light absorption component using a particle size distribution measuring apparatus. As a measurement principle of the particle size distribution measuring apparatus, for example, an image imaging method in which an image of a particle is directly obtained with an electron microscope such as a transmission electron microscope (TEM) and converted into a particle size from the image image, or a particle group Is measured by a laser diffraction / scattering method in which a particle size distribution is obtained by calculation from an intensity distribution pattern of diffraction / scattered light emitted from the laser beam.

  Moreover, when the thickness L of the light absorption layer 4 becomes too small compared with the wavelength λ of light, the light easily passes through the light absorption layer 4 and the light absorption effect of the antireflection material 1 may be lowered. Therefore, it is preferable that the thickness of the light absorption layer 4 satisfies L ≧ λ.

  The screen 200 configured as described above can be used as a screen for projecting an image of the projector 91, for example, as shown in FIG. Specifically, of the visible light, the blue reflection region B having the first uneven structure 11 that reflects only the blue light irradiated by the projector 91, and the green reflection having the second uneven structure 12 that reflects only the green light. The screen 200 may be constituted by the waveguide layer 1 and the clad layer 2 provided with the red reflection region R having the third uneven structure 13 that reflects only the red light in the region G.

  Next, the optical characteristics of the screen of the present invention were calculated using simulation. For the simulation, a software DiffractMOD manufactured by synopsys, Inc was used.

  The screen used for the simulation was composed of a waveguide layer 1 and a cladding layer 2. Here, the waveguide layer is assumed to be a transparent material having a refractive index n = 1.7 and a small extinction coefficient k = 0, and the cladding layer is assumed to be a transparent material having a refractive index n = 1.4 and a small extinction coefficient k = 0. did. The concavo-convex structure of the waveguide layer 1 is a line-and-space, and the line-and-space pitch λ, the width a of the convex portion of the concavo-convex structure, the height b of the convex portion, the thickness c of the waveguide layer 1 (the bottom surface of the concave portion and the cladding) The distance from the layer 2) was as follows.

  FIG. 7 shows the wavelength and light intensity of the reflected light in each region when light is vertically incident on the screen. It can be seen that the wavelength range of the reflected light is changed by changing the pitch P of the pattern.

  When the concavo-convex structure is a line-and-space structure, when the incident wave is tilted parallel to the line direction starting from the vertical, the spectral characteristic of reflection is maintained at about plus or minus 15 °, but tilted in the direction perpendicular to the line direction. It was found that the characteristics could be maintained only about plus or minus 1 °. Therefore, the inclination of the incident wave is desirably parallel to the line direction.

  Next, a method for widening the viewing angle of the screen of the present invention will be described.

  As shown in FIG. 8, the first method of widening the viewing angle is to provide a convex diffusion plate 4 between the blue reflection region B, the green reflection region G, and the red reflection region R. The diffusing plate 4 is preferably made of a material that is transparent to the light reflected by each region. As a result, the light reflected in each region is reflected on the surface of the diffusion plate 4 or the light transmitted through the surface of the diffusion plate 4 is repeatedly reflected in the diffusion plate 4 and then again on the diffusion plate 4. Scattered by exiting from the surface. As a result, the viewing angle of the image projected on the screen can be expanded. The diffusing plate 4 is preferably inclined toward the light incident direction side from the projection means for projecting an image on the screen. Further, the shape of the tip of the diffusion plate 4 is not particularly limited, and it may be sharp like the diffusion plate 4 of FIG. 8 or flat like the diffusion plate 41 of FIG. 9 (1). It may be round like the diffusion plate 42.

  The second method of widening the viewing angle is to make the shape of the convex portions of the first concavo-convex structure 11, the second concavo-convex structure 12, and the third concavo-convex structure 13 not a line but a quadrangle (see FIG. 10) or a circle. .

  The optical properties of the structure were calculated using simulation. For the simulation, a software DiffractMOD manufactured by synopsys, Inc was used.

  The screen used for the simulation was composed of a waveguide layer 1 and a cladding layer 2. Here, the waveguide layer is assumed to be a transparent material having a refractive index n = 1.7 and a small extinction coefficient k = 0, and the cladding layer is assumed to be a transparent material having a refractive index n = 1.45 and a small extinction coefficient k = 0. did. The concavo-convex structure of the waveguide layer 1 is formed by arranging square pillars having a square shape in a square shape. The thickness c of the waveguide layer 1 (distance between the bottom surface of the recess and the clad layer 2) was as follows.

  FIG. 11 shows the wavelength and light intensity of reflected light in each region when light is vertically incident on the screen from the cladding layer side, and FIG. 11 shows each region when light is vertically incident on the screen from the waveguide layer side. FIG. 12 shows the wavelength and light intensity of the reflected light. When the concavo-convex structure was made into a square pillar shape, the spectrum was broad and the reflection angle was wide.

  A third method of widening the viewing angle is to adjust the line and space pitch to make a double period. As shown in FIG. 13, when the double period is used, the secondary Fourier component of the refractive index modulation determines the band gap band of the dispersion characteristic. Therefore, by increasing the secondary Fourier component, the angle tolerance, that is, the viewing angle. Can be increased.

  The illumination light selection device of the present invention is used for the illumination 50 (see FIG. 6) for the space (room) in which the screen of the present invention is disposed, and is irradiated from the illumination. A filter that suppresses transmission of blue light in a predetermined wavelength region, green light in a predetermined wavelength region, and red light in a predetermined wavelength region out of visible light is provided. Here, the blue light in the predetermined wavelength range means blue light reflected by the screen of the present invention, and the green light in the predetermined wavelength range means green light reflected by the screen of the present invention. The area red light means red light reflected by the screen of the present invention. Thereby, since it can suppress that the light of illumination reflects on a screen, the contrast of an image can be improved.

  As the filter, a multilayer interference band filter that cuts light having a wavelength reflected by the screen of the present invention may be used.

  The illumination light selection device may be separately installed in a normal lighting fixture, or may be formed integrally with a cover of the lighting fixture. In these cases, it is preferable that the illumination light selection device includes an attaching / detaching means for attaching / detaching to / from the lighting fixture.

  Further, the lighting fixture itself is composed of a light emitting element such as an LED or an organic EL that emits light other than visible light of blue light in a predetermined wavelength range, green light in a predetermined wavelength range, and red light in a predetermined wavelength range. You may do it.

DESCRIPTION OF SYMBOLS 1 Waveguide layer 2 Clad layer 3 Light absorption layer 4 Scattering plate
11 First relief structure
12 Second uneven structure
13 Third uneven structure
41 Scatter plate
42 Scatter plate
50 lighting
100 screen
200 screen B Blue reflection area B
G Green reflection area G
R Red reflection area R
L light

Claims (14)

A waveguiding layer having a concavo-convex structure and having a plurality of types of reflection regions on the surface for reflecting light in a predetermined wavelength range;
A cladding layer having a refractive index lower than the refractive index of the material of the waveguide layer;
A screen characterized by comprising.   The screen according to claim 1, further comprising a light absorption layer that absorbs light transmitted through the cladding layer.   The waveguide layer has a first concavo-convex structure as a reflection region and reflects blue light in a predetermined wavelength range, and a green reflection that has a second concavo-convex structure and reflects green light in a predetermined wavelength range. 3. The screen according to claim 1, wherein the screen has a region and a red reflection region having a third uneven structure and reflecting red light in a predetermined wavelength region. 4.   The first concavo-convex structure is a periodic structure having a resonant wavelength peak between 400 and 490 nm, and the second concavo-convex structure is a periodic structure having a resonant wavelength peak between 495 and 570 nm. 4. The screen according to claim 3, wherein the third concavo-convex structure is a periodic structure having a resonating light wavelength peak between 610 and 750 nm.   5. The screen according to claim 3, wherein a planar shape of the convex portions of the first concavo-convex structure, the second concavo-convex structure, and the third concavo-convex structure is a quadrangle or a circle.   5. The screen according to claim 3, wherein each of the first concavo-convex structure, the second concavo-convex structure, and the third concavo-convex structure includes a double periodic grating.   The screen according to claim 3, further comprising a diffusion plate between the blue reflection area, the green reflection area, and the red reflection area.   The screen according to any one of claims 3 to 7, wherein each of the blue reflection region, the green reflection region, and the red reflection region has a size in which a unit region is contained in a circle having a diameter of 300 µm.   The light absorption layer is made of a material containing a light absorption component that absorbs light transmitted through the waveguide layer, and the average particle diameter of the light absorption component particles is less than or equal to one-half of the wavelength of light to be absorbed. The screen according to claim 2, wherein the screen is provided.   An illumination light selection device comprising a filter that suppresses transmission of blue light in a predetermined wavelength region, green light in a predetermined wavelength region, and red light in a predetermined wavelength region out of visible light. The light selection device for illumination is used for illumination for a space in which the screen according to any one of claims 3 to 8 is disposed,
The filter is for suppressing transmission of blue light of a predetermined wavelength range, green light of a predetermined wavelength range, and red light of a predetermined wavelength range reflected by the screen. The illumination light selection device according to 10.   The illumination light selection device according to claim 10 or 11, further comprising attachment / detachment means for attaching / detaching to / from the lighting fixture.   A lighting device comprising a light emitting element that emits light other than blue light in a predetermined wavelength region, green light in a predetermined wavelength region, and red light in a predetermined wavelength region among visible light. The lighting fixture is used for lighting for a space in which a screen according to any one of claims 3 to 8 is disposed,
The light emitting element emits light other than blue light having a predetermined wavelength range, green light having a predetermined wavelength range, and red light having a predetermined wavelength range reflected by the screen. 12. A lighting apparatus according to 12.

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