PROJECTION APPARATUS

• US 20170010473A1
• Filed: 02/20/2015
• Published: 01/12/2017
• Est. Priority Date: 02/27/2014
• Status: Active Grant

• Current Assignee: Citizen Watch Co Limited (Citizen Electronics Company Limited)
• Original Assignee: Citizen Holdings Co., Ltd. (Citizen Electronics Company Limited)
• Inventors: IDE, Masafumi
• Granted Patent: US 9,798,153 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G02B 2027/0134 of stereoscopic type
• CPC Class Codes: G02B 2027/0178 Eyeglass type eyeglass details G02C
• CPC Class Codes: G02B 2027/0187 slaved to motion of at least a part of the body of the user, e.g. head, eye
• CPC Class Codes: G02B 26/0833 the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD G02B26/0825 takes precedence; micromechanical devices in general B81B
• CPC Class Codes: G02B 26/101 with both horizontal and vertical deflecting means, e.g. raster or XY scanners colour television using laser beams scanning a display screen H04N9/3129
• CPC Class Codes: G02B 27/0093 with means for monitoring data relating to the user, e.g. head-tracking, eye-tracking
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G02B 3/0056 arranged along two different directions in a plane, e.g. honeycomb arrangement of lenses G02B3/0043 takes precedence; miniaturised objectives for electronic devices employing wafer level optics G02B13/0085
• CPC Class Codes: G02B 30/27 involving lenticular arrays
• CPC Class Codes: G02B 30/40 giving the observer of a single two-dimensional [2D] image a perception of depth
• CPC Class Codes: G02B 6/06 the relative position of the fibres being the same at both ends, e.g. for transporting images
• CPC Class Codes: G03B 21/208 Homogenising, shaping of the illumination light
• CPC Class Codes: H04N 13/305 using lenticular lenses, e.g. arrangements of cylindrical lenses
• CPC Class Codes: H04N 9/3129 scanning a light beam on the display screen scanning a light beam on a screen in displays other than projection devices G09G3/02; scanning systems in general G02B26/10; projectors using laser light sources in general H04N9/3161
• CPC Class Codes: H04N 9/3161 using laser light sources using laser beams scanning the display screen H04N9/3129

Abstract

Provided is a projection apparatus for projecting an image which can be seen stereoscopically, wherein the apparatus is made smaller and the definition of the projected image is higher than would be the case if the present configuration were not employed. The projection apparatus is an apparatus for projecting an image which can be seen stereoscopically, by scanning with one set of at least red, green, and blue laser beams, and includes a light source section that emits the laser beams, a scan section that scans a projection region two-dimensionally with the laser beams, and a microlens array that includes microlenses on which the laser beams from the scan section are incident and that changes emission angles of the laser beams in accordance with incident positions of the laser beams on the microlenses to create a light ray field in which light rays whose positions and directions are controlled are emitted from each point on surfaces of the microlenses in accordance with an image to be projected.

Claims

1. A projection apparatus for projecting an image which can be seen stereoscopically, by scanning with one set of at least red, green, and blue laser beams, the projection apparatus comprising:

a light source section that emits the laser beams;

a scan section that scans a projection region two-dimensionally with the laser beams;

a microlens array that includes a plurality of microlenses on which the laser beams from the scan section are incident and that changes emission angles of the laser beams in accordance with incident positions of the laser beams on the microlenses to create a light ray field in which light rays whose positions and directions are controlled are emitted from each point on surfaces of the microlenses in accordance with an image to be projected;

a projection lens that makes the laser beams emitted from the light source section be collimated beams and makes the collimated beams enter the scan section; and

a second projection lens on which the laser beams from the scan section are incident, the second projection lens converting the laser beams into converged beams passing positions depending on incident angles of the laser beams and makes the converged beams enter the microlens array,

wherein the second projection lens and the microlens array are disposed at an interval so that a rear focal plane of the second projection lens approximately overlaps with a front focal plane of the microlens array.

4. The projection apparatus according to claim 1, further comprising a control section that controls a position of an image formed by the laser beams on a virtual display plane, on which the laser beams are converged, between the second projection lens and the microlens array so that a depth position of a projected image can be recognized.

6. The projection apparatus according to claim 1, wherein

the scan section is a MEMS mirror that scans the projection region by reflecting the laser beams, and

the MEMS mirror is disposed away from the second projection lens, near a front focal position of the second projection lens.

7. The projection apparatus according to claim 1, wherein

the light source section emits a plurality of sets of laser beams from emission ends of a plurality of fibers, and

the scan section scans the projection region two-dimensionally with the plurality of sets of laser beams so that scan images of laser beams with the same color from different sets do not overlap with each other.

8. The projection apparatus according to claim 7, wherein the light source section comprises:

a plurality of first laser elements that emits red laser beams;

a plurality of first fibers that guides the red laser beams emitted from the plurality of first laser elements;

a plurality of second laser elements that emits green laser beams;

a plurality of second fibers that guides the green laser beams emitted from the plurality of second laser elements;

a plurality of third laser elements that emits blue laser beams;

a plurality of third fibers that guides the blue laser beams emitted from the plurality of third laser elements; and

a fiber bundle combiner that fixes emission ends of the first, the second, and the third fibers to form a fiber bundle, wherein

the first, the second, and the third fibers emit the plurality of sets of laser beams from the emission ends.

9. The projection apparatus according to claim 7, wherein the scan section scans each partial region included in the projection region with laser beams corresponding to the partial region among the plurality of sets of laser beams at such a scan angle that the scan images of the laser beams with the same color from the different sets do not overlap with each other.

10. The projection apparatus according to claim 7, wherein

the light source section emits the plurality of sets of laser beams at intervals so that scan lines of the respective sets of laser beams are displaced from each other, and

the scan section scans the projection region with the plurality of sets of laser beams simultaneously.

2. (canceled)

3. (canceled)

5. (canceled)