A cooling device of a projection display apparatus includes a first heat receiving unit including an opening that is rectangular. The first heat receiving unit includes a flow path part that forms the opening. An image display element of the projection display apparatus includes a first front face located in front of a reflective image display, a second front face parallel to the first front face and located behind and outside the first front face, and a first side face located between the first front face and the second front face. The first front face is inserted into the opening, and the flow path part is in contact with the first side face and the second front face via a heat conductive member. The flow path part includes a front face that is flush with or in front of the first front face of the image display element.

Provided is a semiconductor laser device including a plurality of semiconductor laser units LDC that are capable of being independently driven, and a spatial light modulator SLM that is optically coupled to a group of the plurality of semiconductor laser units LDC. Each of the semiconductor laser units includes a pair of clad layers having an active layer 4 interposed therebetween, and a diffractive lattice layer 6 that is optically coupled to the active layer 4. The semiconductor laser device includes a ¼ wavelength plate 26 that is disposed between a group of the active layers 4 of the plurality of semiconductor laser units LDC and a reflection film 23, and a polarizing plate 27 that is disposed between the group of the active layers 4 of the plurality of semiconductor laser units LDC and a light emitting surface.

A projection system includes an illumination light source configured to emit an illumination light beam, a monitor light source configured to emit a monitor light beam, and a projector configured to project both the illumination light beam and the monitor light beam into a projected combined light beam. A first portion of the projected combined light beam is propagated over a first beam path in a first direction, causing an eye of a user to see a display image. A second portion of the projected combined light beam is propagated over a second beam path in a second direction, causing a monitor camera to capture a monitor image. The monitor image is analyzed to determine an orientation or a position of the monitor image. In response to determining that the monitor image is not properly oriented or positioned, an orientation or position of the projector or the illumination image is adjusted.

Illuminations systems that separate different colors into laterally displaced beams may be used to direct different color image content into an eyepiece for displaying images in the eye. Such an eyepiece may be used, for example, for an augmented reality head mounted display. Illumination systems may be provided that utilize one or more waveguides to direct light from a light source towards a spatial light modulator. Light from the spatial light modulator may be directed towards an eyepiece. Some aspects of the invention provide for light of different colors to be outcoupled at different angles from the one or more waveguides and directed along different beam paths.

A projection image display device of the present disclosure includes a light source, an image forming element that forms an image, a color separating and combining unit that separates first illumination light and second illumination light, and combines first projection light and second projection light reflected by the image forming element, and a notch filter that is disposed between the light source and the color separating and combining unit. A first dichroic filter reflects the first illumination light and the first projection light. A first incident angle of the first illumination light with respect to the first dichroic filter is different from a second incident angle of the first projection light with respect to the first dichroic filter. The notch filter attenuates light in a first wavelength band including a boundary between a wavelength band of the first illumination light and a wavelength band of the second illumination light.

A light source device includes a first light source configured to emit first color light, a wavelength conversion element configured to convert a wavelength of excitation light made incident thereon and emit converted light having a wavelength larger than the wavelength of the excitation light, and an emission-position changing mechanism configured to change an emission position of the incident excitation light to thereby change an incident position of the excitation light on the wavelength conversion element and change an emission position of the first color light and an emission position of the converted light in the same direction in synchronization with each other.

A wavelength conversion module is configured to receive an excitation beam. The wavelength conversion module includes a substrate and a wavelength conversion material arranged on the substrate. The substrate includes a ring-shaped light irradiation region, and the wavelength conversion material is annularly arranged on at least part of the ring-shaped light irradiation region. A first color light obtained through conversion when the excitation beam is incident to the wavelength conversion material of the ring-shaped light irradiation region in a first time sequence has a first light intensity, the first color light obtained through conversion when the excitation beam is incident to the wavelength conversion material of the ring-shaped light irradiation region in a second time sequence has a second light intensity, and the first light intensity and the second light intensity are different. In addition, a projection device is also provided.

An image display apparatus according to an embodiment of the present technology includes a polarizer, a polarization conversion element, and a ¼ wave plate. The polarizer causes to transmit linearly polarized light having a predetermined polarization direction. The polarization conversion element converts a polarization state of the linearly polarized light transmitted through the polarizer and emits the light as light in a non-polarized state. The ¼ wave plate is arranged on an optical path of the light in the non-polarized state emitted from the polarization conversion element.

In one embodiment, the system may receive a target pixel value for a pixel of an image of a series of images. The system may determine an error-modified target pixel value based on the target pixel value and a first error value. The system may generate a quantized pixel value corresponding to the error-modified target pixel value for display by the pixel of the image. The system may determine an aggregated representation of quantized pixel values displayed by the pixel of the image and corresponding pixels of one or more preceding images of the series of images. The system may determine a second error value based on the aggregated representation of the quantized pixel values and the first error-modified target pixel value. The system may dither at least a portion of the second error value to at least a corresponding pixel of a next image in the series of images.

The present invention includes systems and methods for a multi-primary color system for display. A multi-primary color system increases the number of primary colors available in a color system and color system equipment. Increasing the number of primary colors reduces metameric errors from viewer to viewer. One embodiment of the multi-primary color system includes Red, Green, Blue, Cyan, Yellow, and Magenta primaries. The systems of the present invention maintain compatibility with existing color systems and equipment and provide systems for backwards compatibility with older color systems.