METHOD AND APPARATUS FOR HEAD WORN DISPLAY WITH MULTIPLE EXIT PUPILS

• US 20160033771A1
• Filed: 03/25/2014
• Published: 02/04/2016
• Est. Priority Date: 03/25/2013
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Ecole polytechnique fãdãrale de lausanne epfl (Schweizerische Eidgenossenschaft)
• Inventors: TREMBLAY, ERIC, GUILLAUMEE, MICKAEL, MOSER, CHRISTOPHE
• Granted Patent: US 9,846,307 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G02B 2027/011 comprising device for correcting geometrical aberrations, distortion
• CPC Class Codes: G02B 2027/0112 comprising device for genereting colour display
• CPC Class Codes: G02B 2027/0125 Field-of-view increase by wavefront division
• CPC Class Codes: G02B 2027/014 comprising information/image processing systems
• CPC Class Codes: G02B 2027/0174 holographic
• 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 26/10 Scanning systems
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G02B 5/188 Plurality of such optical elements formed in or on a supporting substrate
• CPC Class Codes: G02B 5/189 Structurally combined with optical elements not having diffractive power
• CPC Class Codes: G03H 1/0402 Recording geometries or arrangements G03H1/0443, G03H1/0476, G03H1/16 take precedence
• CPC Class Codes: G03H 2001/0439 for recording Holographic Optical Element [HOE]
• CPC Class Codes: G03H 2001/266 Wavelength multiplexing
• CPC Class Codes: G03H 2222/12 Single or narrow bandwidth source, e.g. laser, light emitting diode [LED]
• CPC Class Codes: G03H 2222/13 Multi-wavelengths wave with discontinuous wavelength ranges G03H2222/18 takes precedence

Abstract

A method for displaying an image viewable by an eye, the image being projected from a portable head worn display, comprises steps of: emitting a plurality of light beams of wavelengths that differ amongst the light beams; directing the plurality of light beams to a scanning mirror; modulating in intensity each one of the plurality of light beams in accordance with intensity information provided from the image, whereby the intensity is representative of a pixel value within the image; scanning the plurality of light beams in two distinct axes with the scanning mirror to form the image; and redirecting the plurality of light beams to the eye using a holographic optical element acting as a reflector of the light beams, whereby the redirecting is dependent on the wavelength of the light beam, to create for each light beam an exit pupil at the eye that is spatially separated from the exit pupils of the other light beams.

Claims

1-75. -75. (canceled)

76. A method comprising:

emitting a plurality of light beams, a wavelength of at least one of the plurality of light beams to differ from a wavelength of at least one other of the plurality of light beams;

modulating an intensity of at least one of the plurality of light beams based at least in part on intensity information corresponding to an image to be projected;

scanning the plurality of light beams in two distinct axes to form the image; and

redirecting the plurality of light beams to a plurality of exit pupils based at least in part on the wavelengths of each of the light beams to project the image at the plurality of exit pupils.

77. The method of claim 76, wherein a first exit pupil of the plurality of exit pupils is spatially separated from a second exit pupil of the plurality of exit pupils.

78. The method of claim 76, wherein the intensity of the light beams is representative of pixel values within the image.

79. The method of claim 76, comprising:

forming a first bundle of light beams, each light beam of the first bundle of light beams to have a wavelength substantially within a range of wavelengths of a first spectral band of color to be perceived by human vision; and

redirecting each light beam of the first bundle of light beams to a different one of the plurality of exit pupils.

80. The method of claim 79, comprising:

forming a second bundle of light beams, each light beam of the second bundle of light beams to have a wavelength substantially within a range of wavelengths of a second spectral band of color to be perceived by human vision;

forming a third bundle of light beams, each light beam of the third bundle of light beams to have a wavelength substantially within a range of wavelengths of a third spectral band of color to be perceived by human vision;

redirecting each light beam of the second bundle of light beams to a different one of the plurality of exit pupils; and

redirecting each light beam of the third bundle of light beams to a different one of the plurality of exit pupils.

81. The method of claim 76, comprising applying, for each of the light beams of the plurality of light beams, one or more of image registration or image distortion correction to the image to align the projected image based on the spatial location of the plurality of exit pupils relative to each other.

82. The method of claim 76, comprising spatially arranging the plurality of exit pupils to form an enlarged eyebox for viewing the image.

83. The method of claim 76, comprising combining the plurality of light beams coaxially to correct angular differences between the plurality of light beams corresponding to each of the plurality of exit pupils.

84. A system comprising:

a light source, the light source to emit a plurality of light beams, a wavelength of at least one of the plurality of light beams to differ from a wavelength of at least one other of the plurality of light beams;

a scanning mirror to scan the plurality of light beams in two distinct axes to form an image; and

a holographic optical element to receive the scanned plurality of light beams from the scanning mirror and to redirect the plurality of light beams to a plurality of exit pupils based at least in part on the wavelengths of each of the light beams to project the image at the plurality of exit pupils.

85. The system of claim 84, the light source to modulate an intensity of at least one of the plurality of light beams based at least in part on intensity information corresponding to an image to be projected;

86. The system of claim 85, wherein the intensity of the light beams is representative of pixel values within the image.

87. The system of claim 84, wherein a first exit pupil of the plurality of exit pupils is spatially separated from a second exit pupil of the plurality of exit pupils.

88. The system of claim 84, the holographic optical element to form a first bundle of light beams, each light beam of the first bundle of light beams to have a wavelength substantially within a range of wavelengths of a first spectral band of color to be perceived by human vision, the holographic optical element to redirect each light beam of the first bundle of light beams to a different one of the plurality of exit pupils.

89. The system of claim 88, the holographic optical element to forming a second bundle of light beams, each light beam of the second bundle of light beams to have a wavelength substantially within a range of wavelengths of a second spectral band of color to be perceived by human vision, the holographic optical element to redirect each light beam of the second bundle of light beams to a different one of the plurality of exit pupils.

90. The system of claim 89, the holographic optical element to form a third bundle of light beams, each light beam of the third bundle of light beams to have a wavelength substantially within a range of wavelengths of a third spectral band of color to be perceived by human vision, the holographic optical element to redirect each light beam of the third bundle of light beams to a different one of the plurality of exit pupils.

91. The system of claim 84, comprising

an image processor to apply, for each of the light beams of the plurality of light beams, one or more of image registration or image distortion correction to the image to align the projected image based on the spatial location of the plurality of exit pupils relative to each other.

92. The system of claim 84, the holographic optical element to spatially arrange the plurality of exit pupils to form an enlarged eyebox for viewing the image.

93. The system of claim 84, comprising a combiner lens to combine the plurality of light beams coaxially to correct angular differences between the plurality of light beams corresponding to each of the plurality of exit pupils.

94. An apparatus comprising:

a substrate;

a plurality of kinoform mirrors embedded in the transparent substrate to receive a plurality of light beams corresponding to an image to be projected; and

a reflective layer disposed on the plurality of kinoform mirrors to redirect the plurality of light beams to a plurality of exit pupils to project the image to the plurality of exit pupils.

95. The apparatus of claim 94, the substrate a transparent substrate to transmit ambient light through the substrate.

96. The apparatus of claim 94, wherein the substrate is a polymer matix.

97. The apparatus of claim 94, wherein the plurality of exit pupils are spatially separated from each other.

98. The apparatus of claim 94, comprising a head mounted device, wherein the substrate comprising the embedded kinoform mirrors is coupled to the head mounted device.