# US 2019/0170919 A1 · Optical laminate

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- Number: US 2019/0170919 A1
- Document ID: US20190170919A1
- Status: Published application
- Kind: A1
- Application number: 16/253,212
- Filed: 2019-01-21
- Published: 2019-06-06
- Earliest claimed: 2016-08-30
- Assignees: FUJIFILM Corporation
- Applicants: Fujifilm Corporation
- Inventors: Yukito SAITOH; Daisuke KASHIWAGI
- Web page: https://patentgrep.com/patent/US20190170919A1

## CPC

- G02B 3/0056: {arranged along two different directions in a plane, e.g. honeycomb arrangement of lenses (G02B3/0043 takes precedence; miniaturised objectives for electronic devices employing wafer level optics G02B13/0085)}
- G02B 5/26: Reflecting filters (G02B5/28 takes precedence)
- G02B 3/0087: {with index gradient}
- G02B 5/18: Diffraction gratings {(holographic optical elements G02B5/32, G03H; integrally combined with optical fibres G02B6/02057; for coupling light guides G02B6/34; integrally combined with optical integrated light guides G02B6/12; grating systems G02B27/44)}
- G02B 5/286: {having four or fewer layers, e.g. for achieving a colour effect}
- G02B 5/287: {comprising at least one layer of organic material}
- G02B 5/30: Polarising elements (light-modulating devices with active elements G02F1/00)
- G02B 5/3016: {involving passive liquid crystal elements (optical properties of liquid crystals G02F1/0063; polarising elements associated with active liquid crystal devices G02F1/133528)}
- G02B 5/3083: {Birefringent or phase retarding elements (G02B5/3008, G02B5/3016 take precedence; systems for polarisation control G02B27/286; manufacturing phase modulating patterns by lithographic processes G03F7/001)}
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS

## Abstract

An optical laminate includes a wavelength selective reflective element which is provided with a reflection layer selectively reflecting light in a specific reflection wavelength region, and an absolute phase adjustment layer which is provided on at least one surface side of the wavelength selective reflective element and has optical isotropy, and the absolute phase adjustment layer has an in-plane distribution of at least one of a refractive index or a film thickness, and thus has an in-plane distribution of an optical path length in a film thickness direction.

## Claims

### Claim 1

An optical laminate comprising:
a wavelength selective reflective element which is provided with a reflection layer selectively reflecting light in a specific reflection wavelength region; and
an absolute phase adjustment layer which is provided on at least one surface side of the wavelength selective reflective element and has optical isotropy,
wherein the absolute phase adjustment layer has an in-plane distribution of at least one of a refractive index or a film thickness, and thus has an in-plane distribution of an optical path length in a film thickness direction, and
the optical laminate reflects light in the specific reflection wavelength region by the wavelength selective reflective element, of light incident from the absolute phase adjustment layer side, as reflected light having a wavefront different from a wavefront of the incident light.

### Claim 2 (depends on 1)

The optical laminate according to claim 1,
wherein the reflection layer of the wavelength selective reflective element is formed of a cholesteric liquid crystal layer.

### Claim 3 (depends on 1)

The optical laminate according to claim 1,
wherein the reflection layer of the wavelength selective reflective element is formed of a dielectric multilayer film in which at least two layers having different refractive indices are alternately laminated in multiple layers.

### Claim 4 (depends on 1)

The optical laminate according to claim 1,
wherein the in-plane distribution of the optical path length has a pattern in which the optical path length is changed stepwise.

### Claim 5 (depends on 1)

The optical laminate according to claim 1,
wherein the in-plane distribution of the optical path length has a pattern in which the optical path length is gradually increased with an increase in distance from one point.

### Claim 6 (depends on 1)

The optical laminate according to claim 1,
wherein the in-plane distribution of the optical path length has a pattern in which the optical path length is gradually reduced with an increase in distance from one point.

### Claim 7 (depends on 4)

The optical laminate according to claim 4,
wherein the pattern is periodically repeated.