Image displaying apparatus

• US 9,069,238 B2
• Filed: 10/31/2012
• Issued: 06/30/2015
• Est. Priority Date: 10/31/2011
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Nishina, Kiichiro, Hirakawa, Makoto, Tatsuno, Hibiki, Shibayama, Yasuyuki, Osaka, Takanobu
• Primary Examiner(s): CHOWDHURY, SULTAN U.
• Application Number:
  US13/665,503
• Publication Number:
  US 20130107234A1
• Time in Patent Office: 972 Days
• Field of Search: 353/30, 353/33, 353/37, 353/38, 353/99, 359/196, 359/364, 359/365, 359/379, 359/380, 359/507, 359/512, 359/668, 359/676, 359/820, 348743-747, 349/5, 349 7- 9
• US Class Current: 1/1
• CPC Class Codes: G02B 17/08 Catadioptric systems used in non-imaging applications G02B19/00
• CPC Class Codes: G02B 17/0848 off-axis or unobscured systems in which not all of the mirrors share a common axis of rotational symmetry, e.g. at least one of the mirrors is warped, tilted or decentered with respect to the other elements
• CPC Class Codes: G03B 21/28 Reflectors in projection beam in illumination beam G03B21/2066
• CPC Class Codes: G03F 7/70225 Optical aspects of catadioptric systems, i.e. comprising reflective and refractive elements

Abstract

Disclosed is an image displaying apparatus including an image displaying element configured to form an image to be projected and a projection optical system having a positive refractive power and configured to project the image to be projected onto a screen, wherein the projection optical system includes a lens optical system and a mirror optical system, the lens optical system including plural lens groups, the mirror optical system including a first mirror and a second mirror, the second mirror being a concave mirror, wherein an intermediate image of a pixel of the image displaying element is formed between the image displaying element and the second mirror, and wherein the first mirror is held to be capable of adjusting a position thereof.

Claims

1. An image displaying apparatus comprising:

an image displaying element configured to form an image to be projected; and

a projection optical system having a positive refractive power and configured to project the image to be projected onto a screen,

wherein the projection optical system includes a lens optical system and a mirror optical system, the lens optical system including plural lens groups, the mirror optical system including a first mirror and a second mirror, the second mirror being a concave mirror,

wherein an intermediate image of a pixel of the image displaying element is formed between the image displaying element and the second mirror,

wherein the first mirror is held by a position adjusting part which adjusts a position thereof, the position adjusting part including a plurality of spacers which are inserted between a back face of the first mirror and a back supporting part, the position of the first mirror being adjusted by a thickness of each of the spacers, and

wherein the thickness of each of the spacers is identical thereto and the first mirror is held to be capable of adjusting the position thereof in a direction perpendicular to a reflection surface thereof.

2. The image displaying apparatus as claimed in claim 1, wherein an angle of the image displaying element with respect to the screen is approximately a right angle.

3. The image displaying apparatus as claimed in claim 1, wherein the first mirror is a plane mirror.

4. The image displaying apparatus as claimed in claim 1, wherein the position adjusting part includes three fixation members configured to support the first mirror at three points and three fastening members configured to fix the three fixation members on the back supporting part.

5. The image displaying apparatus as claimed in claim 1, wherein the second mirror is a free-form surface mirror.

6. The image displaying apparatus as claimed in claim 1, wherein the image displaying element is a reflective image displaying element having plural micro-mirrors arranged two-dimensionally and being capable of changing a tilt angle of each of the micro-mirrors between an on-state and an off-state to turn on or off reflection of light therefrom.

7. An image displaying apparatus comprising:

an image displaying element configured to form an image to be projected; and

a projection optical system having a positive refractive power and configured to project the image to be projected onto a screen,

wherein the projection optical system includes a lens optical system and a mirror optical system, the lens optical system including plural lens groups, the mirror optical system including a first mirror and a second mirror, the second mirror being a concave mirror,

wherein an intermediate image of a pixel of the image displaying element is formed between the image displaying element and the second mirror,

wherein the first mirror is held by a position adjusting part which adjusts a position thereof, the position adjusting part including a plurality of spacers which are inserted between a back face of the first mirror and a back supporting part, the position of the first mirror being adjusted by a thickness of each of the spacers, and

wherein the thicknesses of the spacers are different from one another and the first mirror is held to be capable of adjusting a tilt of a reflection surface thereof.

8. The image displaying apparatus as claimed in claim 7, wherein an angle of the image displaying element with respect to the screen is approximately a right angle.

9. The image displaying apparatus as claimed in claim 7, wherein the first mirror is a plane mirror.

10. The image displaying apparatus as claimed in claim 7, wherein the position adjusting part includes three fixation members configured to support the first mirror at three points and three fastening members configured to fix the three fixation members on the back supporting part.

11. The image displaying apparatus as claimed in claim 7, wherein the second mirror is a free-form surface mirror.

12. The image displaying apparatus as claimed in claim 7, wherein the image displaying element is a reflective image displaying element having plural micro-mirrors arranged two-dimensionally and being capable of changing a tilt angle of each of the micro-mirrors between an on-state and an off-state to turn on or off reflection of light therefrom.

13. An image displaying apparatus comprising:

an image displaying element configured to form an image to be projected; and

a projection optical system having a positive refractive power and configured to project the image to be projected onto a screen,

wherein the projection optical system includes a lens optical system and a mirror optical system, the lens optical system including plural lens groups, the mirror optical system including a first mirror and a second mirror, the second mirror being a concave mirror,

wherein an intermediate image of a pixel of the image displaying element is formed between the image displaying element and the second mirror,

wherein the first mirror is held by a position adjusting part which adjusts a position thereof, the position adjusting part including a spacer which is inserted between a back face of the first mirror and a back supporting part, the position of the first mirror being adjusted by a thickness of the spacer, and

wherein the position adjusting part includes a fastening member configured to fix the first mirror and the spacer on the back supporting part, the fastening member passing through the first mirror and the spacer.

14. The image displaying apparatus as claimed in claim 13, wherein an angle of the image displaying element with respect to the screen is approximately a right angle.

15. The image displaying apparatus as claimed in claim 13, wherein the first mirror is a plane mirror.

16. The image displaying apparatus as claimed in claim 13, wherein the second mirror is a free-form surface mirror.

17. The image displaying apparatus as claimed in claim 13, wherein the image displaying element is a reflective image displaying element having plural micro-mirrors arranged two-dimensionally and being capable of changing a tilt angle of each of the micro-mirrors between an on-state and an off-state to turn on or off reflection of light therefrom.