Projector provided with a plurality of image generators

• US 5,333,021 A
• Filed: 12/20/1991
• Issued: 07/26/1994
• Est. Priority Date: 12/27/1990
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Suzuki, Hidetoshi, Mitsutake, Hideaki, Kurematsu, Katsumi, Yoshinaga, Kazuo, Minoura, Nobuo
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): Dowling, William C.
• Application Number:
  US07/811,020
• Time in Patent Office: 949 Days
• Field of Search: 353/31, 353/30, 353/33, 353/34, 353/37, 353/122, 353/82, 359/67, 359/69, 359/62, 359/95, 359/36
• US Class Current: 353/122
• CPC Class Codes: H04N 9/315 Modulator illumination systems general applications of lighting devices F21V; general optical systems G02B; lamp houses for projectors not peculiar to the presence of an electronic spatial light modulator G03B21/20

Abstract

A projector has means for supplying first and second radiation beams, first image generating means for modulating a plurality of portions of the first radiation beam individually and forming a deflected beam and a non-deflected beam to generate a first image, second image generating means for modulating a plurality of portions of the second radiation beam individually and forming a deflected beam and a non-deflected beam to generate a second image, and means for projecting the first and second images onto a predetermined plane by the use of one of the deflected beams and the non-deflected beams from the first and second image generating means, the first and second image generating means emitting the deflected beams so that most of the deflected beam from one of the generating means may substantially not enter the other generating means.

Claims

1. A projector having;

means for supplying first and second radiation beams;

first image generating means for modulating a plurality of portions of said first radiation beam individually and forming a diffused beam and a non-diffused beam to generate a first image;

second image generating means for modulating a plurality of portions of said second radiation beam individually and forming a diffused beam and a non-diffused beam to generate a second image, said second image generating means being provided next said first image generating means; and

means for projecting said first and second images onto a predetermined plane by the use of one of said diffused beams and said non-diffused beams from said first and second image generating means, said first and second image generating means being designed such that said diffused beams have a rotation-asymmetric orientation characteristic, to direct most of said diffused beams from one of said generating means in a direction different from the direction toward the other generating means.

2. A projector according to claim 1, wherein said first and second image generating means each include a liquid crystal device provided with liquid crystal having a first mode for intactly passing an incident beam therethrough and a second mode for scattering said incident beam, and the liquid crystal device(s) of said first and second image generating means scatter said incident beam to thereby effect said diffusion.

3. A projector according to claim 2, wherein said liquid crystal device(s) reflect said portions of said first and second radiation beam, respectively.

4. A projector according to claim 2, wherein said liquid crystal device(s) transmit said portions of said first and second radiation beams, respectively therethrough.

5. A projector according to claim 1, wherein said first and second image generating means each include a liquid crystal device provided with liquid crystal having a first mode for intactly passing an incident beam therethrough and a second mode for diffracting said incident beam, and the liquid crystal device(s) of said first and second image generating means diffract said incident beam to thereby effect said diffusion.

6. A projector according to claim 5, wherein said liquid crystal device(s) reflect said portions of said first and second radiation beams, respectively.

7. A projector according to claim 6. wherein each of said liquid crystal device(s) has;

a pair of transparent substrates facing each other, the surfaces of said pair of transparent substrates which are adjacent to the other of said substrates having transparent electrodes formed thereon;

grating structure formed on said transparent electrode of one of said pair of transparent substrates, a plurality of grooves in said grating structure extending toward the liquid crystal device(s) adjacent image generating means;

a liquid crystal layer having a double refractive property and filling the space between the transparent electrode of the other of said pair of transparent substrate and said grating structure;

drive means using said transparent electrodes to control the direction of orientation of a plurality of liquid crystal molecules in said liquid layer to thereby direct said plurality of liquid crystal molecules in a direction substantially perpendicular to said surfaces and generate said first mode, and direct said plurality of liquid crystal molecules in a direction substantially parallel to said surfaces and generate said second mode; and

reflecting means provided with a λ

/4 plate provided on the side opposite to the side of one of said pair of substrates which is remote from said projecting means and on which said parent electrode is formed and a plane mirror provided on the side of said λ

/4 plate which is opposite to said projecting means, said reflecting means rotating the planes of polarization of both of the polarized components of said incident beam transmitted through said pair of substrates which are orthogonal to each other by approximately 90° and

causing said incident beam to re-enter said pair of substrates.

8. A projector according to claim 5, wherein said liquid crystal device(s) transmitted said portions of said first and second radiation beams, respectively, therethrough.

9. A projector according to claim 8, wherein each of said liquid crystal device(s) has;

first and second transparent substrates facing each other, the surfaces of said transparent substrates which are adjacent to the other of said substrates having transparent electrodes formed thereon;

first grating structure formed on said transparent electrode of one of said first and second transparent substrates, a plurality of grooves in said first grating structure extending toward the liquid crystal device(s) of the adjacent image generating means;

a first liquid crystal layer having a double refractive property and filling the space between the transparent electrode of the other of said first and second transparent substrates and said first grating structure;

third and fourth transparent substrates facing each other, the surfaces of said transparent substrates which are adjacent to the other substrate having transparent electrodes formed thereon, said third and fourth transparent substrates being arranged on the path of said incident beam transmitted through said first and second transparent substrates;

second grating structure formed on said transparent electrode of one of said third and fourth transparent substrates, a plurality of grooves in said second grating structure extending toward the liquid crystal device(s) of said adjacent image generating means;

a second liquid crystal layer having a double refractive property and filling the space between the transparent electrode of the other of said third and fourth transparent substrates and said second grating structure;

drive means using the transparent electrodes of said first and second transparent substrates and the transparent electrodes of said third and fourth transparent substrates to control the directions of orientation of a plurality of liquid crystal molecules in said first and second liquid crystal layers, respectively, to thereby direct said plurality of liquid crystal molecules in each of said liquid crystal layers in a direction substantially perpendicular to said surfaces and generate said first mode, and direct said plurality of liquid crystal molecules in each of said liquid crystal layers in a direction substantially parallel to said surfaces and generate said second mode; and

a λ

/2 plate provided on the path of said incident beam between the set of said first and second transparent substrates and the set of said third and fourth transparent substrates, said λ

/2 plate rotating the planes of polarization of both of the polarized components of said incident beam transmitted through said first and second transparent substrates which are orthogonal to each other by approximately 980° and

causing said incident beam to enter said third and fourth transparent substrates.

10. A projector comprising;

means for supplying radiation beams;

image generating means for modulating a plurality of portions of said radiation beams individually to form diffused beams and non-diffused beams to generate said images;

and means for projecting said images onto a predetermined plane by the use of one of said diffused beams and non-diffused beams from said image generating means,

wherein said diffused beams by way of said image generating means are designed so to have a rotation-asymmetric orientation characteristic.

11. A projector according to claim 10,

wherein said image generating means has a rectangular shape in which the length of the horizontal direction is longer than that of the vertical direction and

said image generating means is designed so that said diffused beams diffuse in said vertical direction.

12. A projector having;

means for supplying first and second radiation beams;

first image generating means for modulating a plurality of portions of said first radiation beam individually and forming a deflected beam and a non-deflected beam to generate a first image;

second image generating means for modulating a plurality of portions of said second radiation beam individually and forming a deflected beam and a non-deflected beam to generate a second image; and

p1 means for projecting said first and second images onto a predetermined plane by the use of one of said deflected beams and said non-deflected beams from said first and second image generating means, said first and second image generating means emitting said deflected beams so that most of said deflected beam from one of said generating means may substantially not enter the other generating means;

wherein said first and second image generating means transmit said portions of said first and second radiation beams, respectively, therethrough.

13. A projector having;

means for supplying first and second radiation beams;

first image generating means for modulating a plurality of portions of said first radiation beam individually and forming a deflected beam and a non-deflected beam to generate a first image;

second image generating means for modulating a plurality of portions of said second radiation beam individually and forming a deflected beam and a non-deflected beam to generate a second image; and

p1 means for projecting said first and second images onto a predetermined plane by the use of one of said deflected beams and said non-deflected beams from said first and second image generating means, said first and second image generating means emitting said deflected beams so that most of said deflected beam from one of said generating means may substantially not enter the other generating means;

wherein said first and second image generating means diffuse said portions of said first and second radiation beams, respectively, to thereby form said deflected beams;

wherein said first and second image generating means diffract said portions of said first and second radiation beams, respectively, to thereby diffuse the same.