Luminous intensity distribution control device and display having the same

• US 6,943,947 B2
• Filed: 09/24/2003
• Issued: 09/13/2005
• Est. Priority Date: 07/10/1998
• Status: Expired due to Fees

• Current Assignee: Maxell, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Adachi, Masaya, Hiyama, Ikuo, Tsumura, Makoto, Minemura, Tetsuro
• Primary Examiner(s): Fuller, Rodney
• Assistant Examiner(s): Cruz, Magda
• Application Number:
  US10/669,052
• Publication Number:
  US 20040057110A1
• Time in Patent Office: 720 Days
• Field of Search: 359452-457, 359/460
• US Class Current: 359/453
• CPC Class Codes: C03C 12/00 Powdered glass C03C8/02 takes precedence; Bead compositions
• CPC Class Codes: G02B 3/0012 characterised by the manufacturing method
• CPC Class Codes: G02B 3/005 arranged along a single direction only, e.g. lenticular sheets G02B3/0043 takes precedence
• CPC Class Codes: 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
• CPC Class Codes: G02B 3/0068 arranged in a single integral body or plate, e.g. laminates or hybrid structures with other optical elements G02B5/1885, G02B17/002, G02B30/27 take precedence
• CPC Class Codes: G02B 5/0226 having particles on the surface
• CPC Class Codes: G02B 5/0242 by means of dispersed particles
• CPC Class Codes: G02B 5/0278 used in transmission
• CPC Class Codes: G02B 7/025 using glue
• CPC Class Codes: G02B 7/027 the lens being in the form of a sphere or ball
• CPC Class Codes: G02F 1/13318 Circuits comprising a photodetector
• CPC Class Codes: G02F 1/133504 Diffusing, scattering, diffracting elements associated to illuminating devices G02F1/133606
• CPC Class Codes: G02F 1/133526 Lenses, e.g. microlenses or Fresnel lenses
• CPC Class Codes: G02F 1/133627 Projection-direct viewing
• CPC Class Codes: G02F 1/133634 the refractive index Nz perpendicular to the element surface being different from in-plane refractive indices Nx and Ny, e.g. biaxial or with normal optical axis
• CPC Class Codes: G02F 1/133638 Waveplates, i.e. plates with a retardation value of lambda/n
• CPC Class Codes: G03B 21/10 Projectors with built-in or built-on screen
• CPC Class Codes: G03B 21/2053 Intensity control of illuminating light controlled by video signal processing H04N5/74 or H04N9/31
• CPC Class Codes: G03B 21/208 Homogenising, shaping of the illumination light
• CPC Class Codes: G03B 21/604 Polarised screens
• CPC Class Codes: H04N 9/3105 : for displaying all colours simultaneously, e.g. by using two or more electronic spatial light modulators simultaneous projection in colour photography G03B33/10; beam splitting or combining systems per se G02B27/10
• CPC Class Codes: H04N 9/3167 : for polarizing the light beam polarizing optical systems per se G02B27/28

Abstract

There is eliminated a fringe pattern produced at the time of incidence of polarized light of a light distribution control element, in which stray light derived from outside unnecessary light in a liquid crystal display apparatus or the like can be effectively reduced, and bright, wide viewing angle characteristics are achieved as viewed at any angle by an observer.

In the light distribution control element (100) constituted of a transparent base member (104), an array of a plurality of micro-lenses (transparent beads 105) densely arranged on the transparent base member and a light absorbing layer having very small opening portions substantially at focal positions of the micro-lenses, the transparent base member is constituted of a transparent body which is substantially isotropic optically or a transparent body having uniaxial optical anisotropy.

Claims

1. A transmission type screen comprising:

a light distribution control element including a transparent base member, a number of micro-lenses densely arranged on one face of the transparent base member and a light absorbing layer having very small opening portions substantially at focal positions of the micro-lenses, the transparent base member being constituted of a transparent body which is substantially isotropic optically or a transparent body having uniaxial optical anisotropy.

2. A transmission type screen as claimed in claim 1, wherein the transparent base member is at least one of:

a glass plate;

an acrylic resin transparent plate; and

a transparent film made of at least one of;

a polycarbonate resin, a vinyl chloride resin, a polyester-based resin, a cellulose-based resin, a polyvinyl alcohol resin and a polyolefin resin.

3. A transmission type screen as claimed in claim 1, comprising the transparent base member being constituted of the transparent body having uniaxial optical anisotropy having an optical axis in a direction in parallel with a face of the transparent base member.

4. A transmission type screen as claimed in claim 1, comprising a non-transparent layer provided between ones of the micro-lenses to absorb any light which attempts transmission in areas between the micro-lenses.

5. A transmission type screen as claimed in claim 1, comprising ones of the micro-lenses having refractive indices in a range of one of:

1.6 through 2.1 and, 1.9 through 2.1.

6. A transmission type screen as claimed in claim 1, comprising ones of the micro-lenses having refractive indices differing from one another.

7. A transmission type screen as claimed in claim 1, comprising ones of the micro-lenses being a transparent bead adhered to the transparent base member.

8. A transmission type screen as claimed in claim 7, comprising ones of transparent beads having a diameter equal to, or smaller than, a half of a pixel pitch.

9. A transmission type screen as claimed in claim 7, comprising ones of transparent beads having 50-80% of a body thereof exposed to a light incident side of the transmission type screen.

10. A transmission type screen as claimed in claim 1, wherein the variation in phase difference produced by the difference in progressing angle of light progressing in said transparent base member after passing through said micro-lenses is equal to or smaller than a half wavelength.

11. A transmission type screen as claimed in claim 1, wherein said micro-lenses are shaped in a rod.

12. A transmission type screen as claimed in claim 1, wherein said micro-lenses are shaped in a sphere.

13. A display comprising:

a light source; and

a transmission type screen including;

a light distribution control element including a transparent base member, a number of micro-lenses densely arranged on one face of the transparent base member and a light absorbing layer having very small opening portions substantially at focal positions of the micro-lenses, the transparent base member being constituted of a transparent body which is substantially isotropic optically or a transparent body having uniaxial optical anisotropy.

14. A display as claimed in claim 13, wherein the transparent base member is at least one of:

a glass plate;

an acrylic resin transparent plate; and

a transparent film made of at least one of;

a polycarbonate resin, a vinyl chloride resin, a polyester-based resin, a cellulose-based resin, a polyvinyl alcohol resin and a polyolefin resin.

15. A display as claimed in the claim 13, comprising the transparent base member being constituted of the transparent body having uniaxial optical anisotropy having an optical axis in a direction in parallel with a face of the transparent base member.

16. A display as claimed in claim 13, comprising a non-transparent layer provided between ones of the micro-lenses to absorb any light which attempts transmission in areas between the micro-lenses.

17. A display as claimed in claim 13, comprising ones of the micro-lenses having refractive indices in a range of one of:

1.6 through 2.1; and

, 1.9 through 2.1.

18. A display as claimed in claim 13, comprising ones of the micro-lenses having refractive indices differing from one another.

19. A display as claimed in claim 13, comprising ones of the micro-lenses being a transparent bead adhered to the transparent base member.

20. A display as claimed in claim 19, comprising ones of transparent beads having a diameter equal to, or smaller than, a half of a pixel pitch.

21. A display as claimed in claim 19, comprising ones of transparent beads having 50-80% of a body thereof exposed to a light incident side of the transmission type screen.

22. A display as claimed in claim 13, wherein the variation in phase difference produced by the difference in progressing angle of light progressing in said transparent base member after passing through said micro-lenses is equal to or smaller than a half wavelength.

23. A display as claimed in claim 13, comprising plural optical switch elements for modulating lights from said light source into optical image lights according to incident image information, said optical image lights being polarized lights,

wherein polarized states of said plural polarized lights modulated by said plural optical switch elements are substantially coincide with each other when said optical image lights are projected onto said transmission type screen.

24. A display as claimed in claim 23, wherein the polarized state of each of said plural polarized lights is circular polarization when projected onto said transmission type screen.

25. A display as claimed in claim 23, wherein the polarized state of each of said plural polarized lights is elliptic polarization when projected onto said transmission type screen.

26. A display as claimed in claim 23, wherein the polarized state of each of said polarized lights is linear polarization when projected onto said transmission type screen.