Image projection apparatus

• US 10,460,637 B2
• Filed: 08/14/2018
• Issued: 10/29/2019
• Est. Priority Date: 08/24/2017
• Status: Active Grant

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Ohkoba, Minoru
• Primary Examiner(s): Dowling, William C.
• Application Number:
  US16/102,854
• Publication Number:
  US 20190066553A1
• Time in Patent Office: 441 Days
• CPC Class Codes: G03B 21/005 Projectors using an electronic spatial light modulator but not peculiar thereto
• CPC Class Codes: G03B 21/142 Adjusting of projection optics
• CPC Class Codes: G03B 21/2033 LED or laser light sources
• CPC Class Codes: G09G 3/002 to project the image of a two-dimensional display, such as an array of light emitting or modulating elements or a CRT
• CPC Class Codes: G09G 3/003 to produce spatial visual effects
• CPC Class Codes: G09G 3/007 Use of pixel shift techniques, e.g. by mechanical shift of the physical pixels or by optical shift of the perceived pixels
• 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 9/317 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
• CPC Class Codes: H04N 9/3188 Scale or resolution adjustment scaling in general G06T3/40; resolution modifying circuits for displays in general G09G5/391

Abstract

An image projection apparatus includes a light modulation element, and a pixel shift unit configured to shift an optical path of light from a pixel in the light modulation element and to shift a position on a projection surface of a projection pixel formed on the projection surface by a projection optical system with the light. The pixel shift unit includes an optical element configured to shift the optical path in one direction among directions orthogonal to an optical axis from the light modulation element to the projection optical system, and a rotating unit configured to change the one direction by rotating the optical element around the optical axis.

Claims

1. An image projection apparatus comprising:

a light modulation element; and

a pixel shift unit configured to shift an optical path of light from a pixel in the light modulation element and to shift a position on a projection surface of a projection pixel formed on the projection surface by a projection optical system with the light,

wherein the pixel shift unit includes;

an optical element configured to shift the optical path in one direction among directions orthogonal to an optical axis from the light modulation element to the projection optical system; and

a rotating unit configured to rotate the optical element around an axis that is parallel to an optical axis direction, so as to change a shift direction of the optical path by the optical element.

2. The image projection apparatus according to claim 1, wherein the optical element is a transmitting member configured to transmit the light or a reflecting member configured to reflect the light, and

wherein the image projection apparatus further includes a holding member configured to hold the optical element while a normal of a transmission surface on the transmitting member or a reflection surface on the reflecting member inclines to the optical axis in the one direction.

3. The image projection apparatus according to claim 1, wherein the optical element is a transmitting member configured to transmit the light or a reflecting member configured to reflect the light, and

wherein the image projection apparatus further includes a holding member configured to swingably hold the optical element so that an inclination of a normal of a transmission surface on the transmitting member or a reflection surface on the reflecting member changes to the optical axis in the one direction.

4. The image projection apparatus according to claim 1, further comprising a controller configured to control a rotating position of the optical element by the rotating unit so as to shift the projection pixel at two or more positions in one rotating period of the optical element by the rotating unit.

5. The image projection apparatus according to claim 4, wherein the controller controls the rotating position of the optical element so as to shift the projection pixel at four positions in the one rotating period.

6. The image projection apparatus according to claim 1, further comprising a controller configured to control a rotating position of the optical element by the rotating unit in accordance with a user input.

7. The image projection apparatus according to claim 1, further comprising a controller configured to control a rotating position of the optical element by the rotating unit in accordance with an input image signal.

8. The image projection apparatus according to claim 1, wherein the rotating unit is configured to rotate the optical element around the axis such that the optical element is rotated on a plane perpendicular to the optical axis.

9. An image projection apparatus comprising:

a light modulation element; and

a pixel shifter configured to shift an optical path of light from a pixel in the light modulation element and to shift a position on a projection surface of a projection pixel formed on the projection surface by a projection optical system with the light,

wherein the pixel shifter includes;

an optical element configured to shift the optical path in one direction among directions orthogonal to an optical axis from the light modulation element to the projection optical system; and

a holder configured to hold the optical element and a motor configured to rotate the holder to thereby rotate the optical element around an axis that is parallel to an optical axis direction, so as to change a shift direction of the optical path by the optical element.

10. The image projection apparatus according to claim 9, wherein the optical element is a transmitting member configured to transmit the light or a reflecting member configured to reflect the light, and

wherein the holder is configured to hold the optical element while a normal of a transmission surface on the transmitting member or a reflection surface on the reflecting member inclines to the optical axis in the one direction.

11. The image projection apparatus according to claim 9, wherein the optical element is a transmitting member configured to transmit the light or a reflecting member configured to reflect the light, and

wherein the holder is configured to swingably hold the optical element so that an inclination of a normal of a transmission surface on the transmitting member or a reflection surface on the reflecting member changes to the optical axis in the one direction.

12. The image projection apparatus according to claim 9, further comprising a controller configured to control the motor so as to control a rotating position of the optical element to thereby shift the projection pixel at two or more positions in one rotating period of the optical element.

13. The image projection apparatus according to claim 12, wherein the controller controls the motor so as to control the rotating position of the optical element to thereby shift the projection pixel at four positions in the one rotating period.

14. The image projection apparatus according to claim 9, further comprising a controller configured to control the motor so as to control a rotating position of the optical element in accordance with a user input.

15. The image projection apparatus according to claim 9, further comprising a controller configured to control the motor so as to control a rotating position of the optical element in accordance with an input image signal.

16. The image projection apparatus according to claim 9, wherein the motor is configured to rotate the holder to thereby rotate the optical element around the axis such that the optical element is rotated on a plane perpendicular to the optical axis.