Image display apparatus

• US 9,860,499 B2
• Filed: 01/29/2016
• Issued: 01/02/2018
• Est. Priority Date: 01/30/2015
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Mizoguchi, Yasushi
• Primary Examiner(s): HOWARD, RYAN D
• Application Number:
  US15/010,176
• Publication Number:
  US 20160227177A1
• Time in Patent Office: 704 Days
• CPC Class Codes: G02B 19/0014 at least one surface having optical power
• CPC Class Codes: G02B 19/0066 in the form of an LED array
• CPC Class Codes: G02B 26/0875 by means of one or more refracting elements
• CPC Class Codes: G02B 27/0905 Dividing and/or superposing multiple light beams
• CPC Class Codes: G02B 27/0922 the semiconductor light source comprising an array of light emitters
• CPC Class Codes: G02B 27/1026 for use with reflective spatial light modulators
• CPC Class Codes: G02B 27/1053 having a single light modulator for all colour channels
• CPC Class Codes: G02B 27/149 using crossed beamsplitting surfaces, e.g. cross-dichroic cubes or X-cubes
• 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 21/147 Optical correction of image distortions, e.g. keystone
• 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 9/3141 Constructional details thereof details not peculiar to the presence of an electronic spatial light modulator G03B21/14
• 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

A projector includes a light source, liquid crystal panels that modulate light emitted from the light source, a dichroic prism that combines modulated light fluxes modulated by the liquid crystal panels with one another into video light and outputs the video light, and a pixel shift device that changes the optical path of the video light output from the dichroic prism. The pixel shift device includes a glass plate on which the video light is incident and an electromagnetic actuator that causes the glass plate to swing. The electromagnetic actuator is arranged in a position outside the dichroic prism and different from the positions of the liquid crystal panels when viewed along the optical axis of the video light.

Claims

1. An image display apparatus comprising:

a light source configured to emit light;

a first spatial light modulator and a second spatial light modulator configured to modulate the light emitted from the light source into first modulated light and second modulated light, respectively;

a dichroic prism configured to combine the first modulated light and the second modulated light into combined light and to output the combined light in an optical axis direction, the dichroic prism being in a cuboid shape, the dichroic prism having a first surface, a second surface opposite to the first surface, and a third surface interconnecting the first and second surfaces, the third surface being perpendicular to the optical axis direction; and

an optical path controller configured to change an optical path of the combined light output from the dichroic prism, the optical path controller having a transparent substrate on which the combined light is incident, an electromagnetic actuator displacing the transparent substrate, and an edge side, the electromagnetic actuator being disposed between the edge side and the transparent substrate,

wherein the third surface is in a rectangular shape and includes a first side, a second side parallel to the first side, a third side interconnecting the first and second sides, and a fourth side parallel to the third side,

the first surface and the third surface of the dichroic prism contacting each other on the first side, and the second surface and the third surface of the dichroic prism contacting each other on the second side,

the first spatial light modulator is disposed to face the first surface of the dichroic prism, and the second spatial light modulator is disposed to face the second surface of the dichroic prism, and

the optical path controller is disposed to face the third surface of the dichroic prism such that a surface of the transparent substrate faces the third surface and the electromagnetic actuator is located closer to the third side than the first and second sides.

2. The image display apparatus according to claim 1,

wherein the electromagnetic actuator is located at a position rotated from a position of the first spatial light modulator around an optical axis of the combined light by an angle greater than or equal to 45°

but smaller than or equal to 135°

when viewed along the optical axis direction.

3. The image display apparatus according to claim 1,

wherein the optical path controller includes:

an optical section;

a movable section that supports the optical section;

a shaft that pivotably supports the movable section around a swing axis; and

a support that supports the shaft, and

the electromagnetic actuator includes;

a permanent magnet provided in the movable section; and

a coil that is disposed so as to face the permanent magnet and the movable section and that produces a magnetic field acting on the permanent magnet.

4. The image display apparatus according to claim 3,

wherein the support has a recess opening toward a surface facing the dichroic prism.

5. The image display apparatus according to claim 3,

wherein the support has a recess opening toward a surface facing away from the dichroic prism.

6. The image display apparatus according to claim 1, further comprising a light modulator holding section that has magnetism and that holds the first spatial light modulator.

7. The image display apparatus according to claim 1,

wherein the electromagnetic actuator is arranged outside the light combining element and in a position that is offset from the first spatial light modulator when viewed in the optical axis direction.

8. The image display apparatus according to claim 1,

wherein the optical path controller is disposed such that the edge side is parallel to the third side.

9. The image display apparatus according to claim 8, further comprising:

a third spatial light modulator that modulates the light emitted from the light source,

wherein the dichroic prism has a fourth surface opposite to the third surface, and

the third spatial light modulator is disposed to face the fourth surface.