Optical projection apparatus, transmission type screen, and projection type image display apparatus

• US 6,894,729 B2
• Filed: 05/30/2003
• Issued: 05/17/2005
• Est. Priority Date: 01/21/1999
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Ogura, Naoyuki, Yatsu, Masahiko, Ikeda, Hidehiro, Hirata, Koji
• Primary Examiner(s): Lee, Michael H.
• Assistant Examiner(s): Natnael, Paulos M.
• Application Number:
  US10/448,218
• Publication Number:
  US 20030202127A1
• Time in Patent Office: 718 Days
• Field of Search: 348/744, 348/750, 348/748, 348756-759, 348/761, 348/762, 359/487, 359/649, 353/31, 353/202, 353 28- 30, 353/34, 353/37
• US Class Current: 348/744
• CPC Class Codes: G02B 13/16 for use in conjunction with image converters or intensifiers , or for use with projectors, e.g. objectives for projection TV
• CPC Class Codes: G03B 21/10 Projectors with built-in or built-on screen
• CPC Class Codes: H04N 5/7441 the modulator being an array of liquid crystal cells
• CPC Class Codes: H04N 9/3108 by using a single electronic spatial light modulator
• CPC Class Codes: H04N 9/3141 Constructional details thereof details not peculiar to the presence of an electronic spatial light modulator G03B21/14
• CPC Class Codes: H04N 9/3144 Cooling systems cooling of liquid crystal cells in general G02F1/133382; cooling of projectors not peculiar to the presence of an electronic spatial light modulator G03B21/16
• CPC Class Codes: H04N 9/317 Convergence or focusing systems electronic adjustment of convergence H04N9/3185; convergence or focusing arrangements for cathode ray tubes H04N9/28; means for automatic focusing of projectors not peculiar to the presence of an electronic spatial light modulator G03B21/53

Abstract

An optical projection apparatus includes an optical lighting system provided with a polarized beam splitter for polarizing white light flux from a white light source and combining the white light flux with other light fluxes, thereby taking out a predetermined polarized wave; a multi-lens array consisting of a plurality of lens elements; and an irradiator for separating the white light flux into three primary color light fluxes of red, green, and blue and irradiating each of the three color light fluxes on the same display element at an angle different from the others; and a projecting lens unit used for projecting the three primary color light fluxes modulated by the display element. Color light fluxes modulated by the display element are separated in a horizontal direction of the screen of the display element when passing an injection pupil of the projection lens unit.

Claims

1. An optical projection apparatus, comprising:

an optical lighting system provided with an irradiating unit to separate white light flux from a white light source into three primary color light fluxes of red, green, and blue, and to irradiate said three color light fluxes on a display element; and

a projection lens unit having a plurality of lens element to project said three color light fluxes modulated by said display element to a screen;

wherein said optical lighting system is disposed between said white light source and said display element;

wherein said blue light flux passes through substantially a center of an injection pupil of said projection lens unit; and

wherein said lens element included in said projection lens unit allows a sign of aberration generated by said red light flux to be substantially opposite to a sign of magnification color aberration generated by said projection lens unit, thereby said aberration generated by said red light flux is corrected in the direction for canceling said magnification color aberration by said projection lens unit.

2. An optical projection apparatus in accordance with claim 1,

wherein said display element includes a liquid crystal panel combined with a polarizing plate;

and

said apparatus further comprising a cooling liquid filled in a pace formed between said liquid crystal panel and a lens element which is close to said liquid crystal panel.

3. An optical projection apparatus in accordance with claim 1, wherein said projection lens unit is provided with a first lens group having a negative refractive power as a whole;

a second lens group having positive refractive power as a whole; and

a third lens group having a negative refractive power as a whole, and including at least a lens element having a negative refractive power at a center portion thereof including the light axis and a positive refractive power at a peripheral portion thereof, said first to third lens groups being disposed in order from the side of said screen.

4. An optical projection apparatus in accordance with claim 3, wherein said projection lens unit is provided with said first, second, and third lens groups disposed in order from said screen side;

said first lens group has a negative refractive power as a whole and includes at least a meniscus lens element having a convex surface facing said screen;

said second lens group has a positive refractive power as a whole and includes at least a lens element obtained by laminating a double-convex lens element having a first Abbe number on a double-convex lens element having an Abbe number smaller than said first Abbe number so as to have a combined negative refractive power; and

said third lens group has a negative refractive power as a whole and includes at least a lens element having a negative refractive power at a center portion thereof including the light axis and a positive refractive power at a peripheral portion thereof.

5. An optical projection apparatus in accordance with claim 2, wherein said polarizing plate is disposed in a space formed between said liquid crystal panel and one of said lens elements of said projection lens unit, which is closest to said liquid crystal panel and is cooled by said cooling liquid.

6. An optical projection apparatus in accordance with claim 1, comprising:

at least two predetermined lens units having a variable pitch therebetween; and

said projection lens unit has an aperture for forming a predetermined image and blocking other light fluxes that are not used for forming said predetermined image by absorbing the other light fluxes.

7. An optical projection apparatus in accordance with claim 6, wherein said aperture is not shaped as a circle.

8. An optical projection apparatus, comprising:

an optical lighting means provided with an irradiating means for separating white light flux from a white light source into three primary color light fluxes of red, green, and blue, and for irradiating said three color light fluxes on display element; and

a projection lens means having a plurality of lens element for projecting said three color light fluxes modulated by said display element to a screen;

wherein said optical lighting means is disposed between said white light source and said display element;

wherein said blue light flux passes through substantially a center of an injection pupil of said projection lens means; and

wherein said lens element included in said projection lens means allows a sign of aberration generated by said red light flux to be different from to be substantially opposite to a sign of magnification color aberration generated by said projection lens means, thereby said aberration generated by said red light flux is corrected in the direction for canceling said magnification color aberration by said projection lens means.

9. An optical projection apparatus in accordance with claim 8,

wherein said display element includes a liquid crystal panel combined with a polarizing plate;

and

said apparatus further comprising a cooling liquid filled in a pace formed between said liquid crystal panel and a lens element which is closest to said liquid crystal panel.

10. An optical projection apparatus in accordance with claim 8, wherein said projection lens means is provided with first lens group having a negative refractive power as a whole;

a second lens group having a positive refractive power as a whole; and

a third lens group having a negative refractive power as a whole, and including at least a lens element having a negative refractive power at a center portion thereof including the light axis and a positive refractive power at a peripheral portion thereof, said first to third lens groups being disposed in order from the side of said screen.

11. An optical projection apparatus in accordance with claim 10, wherein said projection lens means is provided with aid first, second, and third lens groups disposed in order from said screen side;

said first lens group has a negative refractive power as a whole and includes at least a meniscus lens element having a convex surface facing said screen;

said second lens group has a positive refractive power as a whole and includes at least a lens element obtained by laminating a double-convex lens element having a first Abbe number on a double-convex lens element having an Abbe number smaller than said firs Abbe number so as to have a combined negative refractive power; and

said third lens group has a negative refractive power as a whole and includes at least a lens element having a negative refractive power at a center portion thereof including the light axis and a positive refractive power at a peripheral portion thereof.

12. An optical projection apparatus in accordance with claim 9, wherein said polarizing plate is disposed in a space formed between said liquid crystal panel and one of said lens elements of said projection lens means, which is closest to said liquid crystal panel and is cooled by said cooling liquid.

13. An optical projection apparatus in accordance with claim 8, comprising:

at least two predetermined lens units having a variable pitch therebetween; and

said projection lens means has an aperture for forming a predetermined image and blocking other light fluxes that are not used for forming aid predetermined image by absorbing the other light fluxes.

14. An optical projection apparatus in accordance with claim 13, wherein said aperture is not shaped as a circle.