IMAGE DISPLAYING APPARATUS

• US 20130107234A1
• Filed: 10/31/2012
• Published: 05/02/2013
• Est. Priority Date: 10/31/2011
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Kiichiro Nishina
• Inventors: Hirakawa, Makoto, Tatsuno, Hibiki, Shibayama, Yasuyuki, Osaka, Takanobu, NISHINA, Kiichiro
• Granted Patent: US 9,069,238 B2
• Time in Patent Office: Days
• US Class Current: 353/99
• 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, and

wherein the first mirror is held to be capable of adjusting a position 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, further comprising:

a back supporting part; and

a position adjusting part configured to hold the first mirror with respect to the back supporting part, the position adjusting part including three fixation members configured to support the first mirror at three points, three fastening members configured to fix the three fixation members on the back supporting part, and three spacers inserted between a back face of the first mirror and the back supporting part,

wherein a position of the first mirror is adjusted by a thickness of each of the spacers.

5. The image displaying apparatus as claimed in claim 4, wherein a thickness of each of the spacers is identical thereto and the first mirror is held to be capable of adjusting a position thereof in a direction perpendicular to a reflection surface thereof.

6. The image displaying apparatus as claimed in claim 4, wherein 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.

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

8. 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.