Liquid crystal device with anti-reflection function in dielectric layer

• US 4,556,288 A
• Filed: 10/22/1982
• Issued: 12/03/1985
• Est. Priority Date: 10/27/1981
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Sekimura, Nobuyuki
• Primary Examiner(s): Gron, Teddy S.
• Assistant Examiner(s): SCALZO, CATHERINE KILBY
• Application Number:
  US06/435,961
• Time in Patent Office: 1,138 Days
• Field of Search: 350/334, 350/338, 350/336, 350/339 R, 350/339 D, 350/339 F, 350/340, 350/341, 350/347 R, 350/347 V, 350/348, 252/299.01
• US Class Current: 349/137
• CPC Class Codes: G02B 1/115 Multilayers
• CPC Class Codes: G02F 1/133502 Antiglare, refractive index matching layers

Abstract

A liquid crystal device wherein the liquid crystal is sandwiched between electrode-substrates. At least one of the electrode-substrates is composed of a transparent substrate, a transparent electrode formed thereon and a transparent dielectric layer formed on the electrode and having a refractive index changing continuously or stepwise in the direction of thickness, thereby reducing the light to be reflected by the transparent electrode.

Claims

1. A liquid crystal device with an anti-reflection function comprising:

a liquid crystal; and

two electrode-substrates so positioned as to sandwich said liquid crystal therebetween, at least one of said substrates including a transparent substrate, a transparent electrode provided thereon, and a dielectric layer provided on said electrode and facing said liquid crystal, said dielectric layer comprising a single layer and having a refractive index which decreases in the direction of thickness thereof from the side of said transparent electrode toward the side of said liquid crystal to reduce the light in the visible wavelength range to be reflected by said electrode.

2. A liquid crystal device according to claim 1, wherein the device satisfies the following relation:

n₀ <

n₁ and n₃ >

n_LC, where n₀ is the refractive index of said transparent substrate, n₁ is that of said transparent electrode, n₃ is that of said dielectric layer at a side thereof facing the liquid crystal, and n_LC is that of the liquid crystal.

3. A liquid crystal device according to claim 1 or 2, wherein the optical thickness of said transparent electrode and said dielectric layer satisfy the following relation:

##EQU20## where d₁ is the geometrical thickness of said transparent electrode, n(d) is the refractive index of said dielectric layer, d₂ is the geometrical thickness thereof, λ

is the design wavelength, and N₁ and N₂ are arbitrary positive integers.

4. A liquid crystal device according to claim 1 or 2, wherein the optical thickness of said transparent electrode and said dielectric layer satisfy the following relation:

##EQU21## where d₁ is the geometrical thickness of said transparent electrode, n(d) is the refractive index of said dielectric layer, d₂ is the geometrical thickness thereof, λ

is the design wavelength, and N₁ and N₂ are arbitrary positive integers.

5. A liquid crystal device according to claim 1 or 2, wherein the optical thickness of said transparent electrode and said dielectric layer satisfy following relation:

##EQU22## where d₁ is the geometrical thickness of said transparent electrode, n(d) is the refractive index of said dielectric layer, d₂ is the geometrical thickness thereof, λ

is the design wavelength, and N₁ and N₂ are arbitrary positive integers.

6. A liquid crystal device according to claim 1 or 2, wherein the optical thicknesses of said transparent electrode and said dielectric layer satisfy following relation:

##EQU23## where d₁ is the geometrical thickness of said transparent electrode, n(d) is the refractive index of said dielectric layer, d₂ is the geometrical thickness thereof, λ

is the design wavelength, and N₁ and N₂ are arbitrary positive integers.