Half mirror for displaying projected image and projected image display system

Patent metadata

Field	Value
Publication number	US-2016209652-A1
Application number	US-201615086452-A
Country	US
Kind code	A1
Filing date	Mar 31, 2016
Priority date	Oct 3, 2013
Publication date	Jul 21, 2016
Grant date	—

Abstract

Provided are a half mirror for displaying a projected image having visible light transmittance, in which the selective reflection layer includes at least one layer formed by immobilizing a cholesteric liquid crystalline phase (for example, three or more layers formed by immobilizing a cholesteric liquid crystalline phase which exhibit different center wavelengths of selective reflection), and a transparent medium on at least one surface side of the selective reflection layer, and the transparent medium includes an inclined surface having an angle of 1° to 30° with respect to the surface of the selective reflection layer on the transparent medium side, and a projected image display system including the half mirror for displaying a projected image and a projector. The half mirror for displaying a projected image of the present invention is useful as a combiner of a head up display or the like.

First claim

What is claimed is:

1 . A half mirror for displaying a projected image having visible light transmittance, comprising:
a selective reflection layer, wherein the selective reflection layer includes at least one layer formed by immobilizing a cholesteric liquid crystalline phase, and a transparent medium on at least one surface side of the selective reflection layer, and the transparent medium includes an inclined surface having an angle of 1° to 30° with respect to a surface of the selective reflection layer on the transparent medium side.

2 . The half mirror for displaying a projected image according to claim 1 ,
wherein the transparent medium is directly in contact with the selective reflection layer or directly adheres to the selective reflection layer.

3 . The half mirror for displaying a projected image according to claim 1 ,
wherein the transparent medium is a homogeneous medium.

4 . The half mirror for displaying a projected image according to claim 3 ,
wherein a difference between a refractive index of the transparent medium and an in-plane average refractive index of the selective reflection layer is less than or equal to 0.05.

5 . The half mirror for displaying a projected image according to claim 1 ,
wherein a layer formed by immobilizing a cholesteric liquid crystalline phase is not included on any one surface side of the transparent medium.

6 . The half mirror for displaying a projected image according to claim 1 ,
wherein the inclined surface is on an outermost surface.

7 . The half mirror for displaying a projected image according to claim 1 ,
wherein the transparent medium is included on both side surfaces of the selective reflection layer, and a film thickness is even.

8 . The half mirror for displaying a projected image according to claim 1 ,
wherein the selective reflection layer includes three or more layers formed by immobilizing a cholesteric liquid crystalline phase, and the three or more layers formed by immobilizing the cholesteric liquid crystalline phase exhibit different selective reflection wavelengths.

9 . The half mirror for displaying a projected image according to claim 8 ,
wherein the three or more layers formed by immobilizing the cholesteric liquid crystalline phase are obtained by repeatedly forming another layer formed by immobilizing a cholesteric liquid crystalline phase directly on a surface of a layer formed by immobilizing a cholesteric liquid crystalline phase which is prepared in advance, and other layers are not included between any layers of the three or more layers formed by immobilizing the cholesteric liquid crystalline phase.

10 . The half mirror for displaying a projected image according to claim 1 , further comprising:
a layer formed by immobilizing a cholesteric liquid crystalline phase which has a center wavelength of apparent selective reflection with respect to red light; a layer formed by immobilizing a cholesteric liquid crystalline phase which has a center wavelength of apparent selective reflection with respect to green light; and a layer formed by immobilizing a cholesteric liquid crystalline phase which has a center wavelength of apparent selective reflection with respect to blue light.

11 . The half mirror for displaying a projected image according to claim 7 , further comprising:
a layer formed by immobilizing a cholesteric liquid crystalline phase which has a center wavelength of apparent selective reflection with respect to red light; a layer formed by immobilizing a cholesteric liquid crystalline phase which has a center wavelength of apparent selective reflection with respect to green light; and a layer formed by immobilizing a cholesteric liquid crystalline phase which has a center wavelength of apparent selective reflection with respect to blue light.

12 . A combiner of a head up display, comprising the half mirror for displaying a projected image according to claim 1 .

13 . A combiner of a head up display, comprising the half mirror for displaying a projected image according to claim 10 .

14 . A combiner of a head up display, comprising the half mirror for displaying a projected image according to claim 11 .

15 . A projected image display system, comprising:
a projector; and the half mirror for displaying a projected image according to claim 1 , wherein a light emission wavelength of a light source of the projector is in a selective reflection band of the layer formed by immobilizing the cholesteric liquid crystalline phase.

16 . A projected image display system, comprising:
a projector; and the half mirror for displaying a projected image according to claim 10 , wherein a light emission wavelength of a light source of the projector is in a selective reflection band of the layer formed by immobilizing the cholesteric liquid crystalline phase.

17 . A projected image display system, comprising:
a projector; and the half mirror for displaying a projected image according to claim 11 , wherein a light emission wavelength of a light source of the projector is in a selective reflection band of the layer formed by immobilizing the cholesteric liquid crystalline phase.

18 . The projected image display system according to claim 15 ,
wherein the projector, the transparent medium, and the selective reflection layer are arranged in this order.

19 . A head up display comprising:
a projector; and the combiner according to claim 12 , wherein a light emission wavelength of a light source of the projector is in a selective reflection band of the layer formed by immobilizing the cholesteric liquid crystalline phase.

20 . A head up display comprising:
a projector; and the combiner according to claim 13 , wherein a light emission wavelength of a light source of the projector is in a selective reflection band of the layer formed by immobilizing the cholesteric liquid crystalline phase.

Assignees

• Fujifilm Corp

Inventors

• Ichihashi Mitsuyoshi

Classifications

• G02B2027/0114

  comprising dichroic elements · CPC title

• G02B27/0101 Primary

  characterised by optical features (G02B27/0172 takes precedence) · CPC title

• G02B2027/012

  comprising devices for attenuating parasitic image effects · CPC title

• G02B2027/0194

  with combiner of laminated type, for optical or mechanical aspects · CPC title

• G02B2027/011

  comprising device for correcting geometrical aberrations, distortion · CPC title