Display having diffraction grating pattern

• US 5,301,062 A
• Filed: 01/28/1992
• Issued: 04/05/1994
• Est. Priority Date: 01/29/1991
• Status: Expired due to Term

• Current Assignee: Toppan Printing Co., Ltd. (TOPPAN Holdings, Inc.)
• Original Assignee: Toppan Printing Co., Ltd. (TOPPAN Holdings, Inc.)
• Inventors: Takahashi, Susumu, Toda, Toshiki, Iwata, Fujio
• Primary Examiner(s): Arnold, Bruce Y.
• Assistant Examiner(s): COLLINS, DARRYL J
• Application Number:
  US07/826,869
• Time in Patent Office: 798 Days
• Field of Search: 359/22, 359/23, 359/24, 359/567, 359/569, 359/566
• US Class Current: 359/567
• CPC Class Codes: G02B 5/1842 Gratings for image generation G02B5/1847 takes precedence
• CPC Class Codes: G03H 1/268 Holographic stereogram
• CPC Class Codes: G03H 2001/0497 Dot matrix holograms

Abstract

A display having a diffraction grating pattern includes:

(a) a flat substrate; and

(b) at least one dot formed on a surface of the flat substrate, the dot being formed by a diffraction grating pattern as an aggregate of a plurality of curves obtained by translating a curve.

Claims

1. A display having a diffraction grating pattern, comprising:

(a) a flat substrate;

(b) at least one dot formed on a surface of said flat substrate, the dot being formed by a diffraction grating pattern as an aggregate of a plurality of curves obtained by translating a curve; and

(c) light-shielding means having a predetermined shape and arranged on an illumination light incident side of the diffraction gratings.

2. A display according to claim 1, wherein said light-shielding means is obtained using a printing ink.

3. A display according to claim 1, wherein said light-shielding means is obtained using a spatial modulation element.

4. A display having a diffraction grating pattern, comprising:

(a) a flat substrate;

(b) at least one dot formed on a surface of said flat substrate, the dot being formed by a diffraction grating pattern as an aggregate of a plurality of curves obtained by translating a curve; and

(c) light-shielding means having a predetermined pattern and arranged on a diffracted light emerging side of the diffraction gratings.

5. A display according to claim 4, wherein said light-shielding means is obtained using a printing ink.

6. A display according to claim 4, wherein said light-shielding means is obtained using a spatial modulation element.

7. A display having a diffraction grating pattern, comprising:

(a) a flat substrate; and

(b) at least one dot formed on a surface of said substrate, the dot being formed by a diffraction grating pattern as an aggregate of a plurality of curves obtained by translating a curve;

wherein said curve has a gradient Ω

(omega) which changes from Ω

₁ to Ω

₂ at the extreme left and right portions of the dot and having a pitch d wherein the curve is translated to obtain the plurality of curves with the following conditions satisfied;

space="preserve" listing-type="equation">tan ((omega).sub.1)=sin ((alpha).sub.1)/sin ((theta))

space="preserve" listing-type="equation">tan ((omega).sub.2)=sin ((alpha).sub.2)/sin ((theta))

space="preserve" listing-type="equation">d=(lambda)/sin ((theta))

where (theta)is an incident angle of illumination light, (alpha)₁ and (alpha)₂ are angles (directs of first-order diffracted light) from which the diffraction grating is observed, and (lambda) is a wavelength of the first-order diffracted light.

8. A display according to claim 7, wherein the dot has a region in which no diffraction grating is present.

9. A display according to claim 7, wherein the dot has a region in which no diffraction grating is present, and the region in which no diffraction grating is present is divided by a line parallel to a translation direction of the curve of the diffraction grating.

10. A display having a diffraction grating pattern, comprising:

(a) a flat substrate; and

(b) at least one dot formed on a surface of said substrate, the dot being formed by a diffraction grating pattern as an aggregate of a plurality of curves obtained by translating a curve;

wherein the dot is constituted by an aggregate of a plurality of curves obtained by translating a curve at arbitrary pitches,

if wavelengths of diffracted light components are defined as (lambda)₁, (lambda)₂, . . . , (lambda)_m, . . . , (lambda)_n, and intensities of the light components at respective wavelengths are defined as A₁, A₂, . . . , A_m, . . . , A_n, spatial frequencies (reciprocals of the pitches) of the diffraction gratings required to diffract the light components having the respective wavelengths are defined as follows;

space="preserve" listing-type="equation">f.sub.1 =sin(theta)/(lambda).sub.1

space="preserve" listing-type="equation">f.sub.2 =sin(theta)/(lambda).sub.2

space="preserve" listing-type="equation">f.sub.m =sin(theta)/(lambda).sub.m

space="preserve" listing-type="equation">f.sub.n =sin(theta)/(lambda).sub.n

and

a delta function is defined as (delta)(X), a spatial frequency distribution of F(fx) represented by the following equation is given to the diffraction gratings, and a function obtained by transforming F(fx) in accordance with an inverse Fourier transform is defined as f(x), and the curve is translated to have an f(x) distribution in a translation direction;

##EQU4##

11. A display according to claim 10, wherein the dot has a region in which no diffraction grating is present.

12. A display according to claim 10, wherein the dot has a region in which no diffraction grating is present, and the region in which no diffraction grating is present is divided by a line parallel to a translation direction of the curve of the diffraction grating.