Devices and methods are described herein that use a first solid figure element, a polarizing beam splitter, and a second solid figure element to reduce speckle in projected images. Specifically, laser light is generated and split into two portions having orthogonal polarizations. The first portion of laser light is internally reflected off at least three internal faces of the second solid figure element and is then spatially recombined with the second portion of laser light in the first solid figure element. The difference in path length followed by the two portions generates a temporal incoherence in the recombined laser light beam, and that temporal incoherence reduces speckle in the projected image.

The present invention concerns a method for controlling a laser-based lighting system comprising a scanning mirror arrangement, arranged to be rotatable around two substantially orthogonal axes. The method comprises: (a) a sensor capturing a first image; (b) the sensor sending data representing at least part of the first image to an image generation unit; (c) the image generation unit generating a second image based on the data representing at least part of the first image, wherein the generated second image comprises information representing a feature region in the first image; (d) the image generation unit sending the second image to a projection system controller; and (e) the projection system controller, based on the received second image, controlling the operation of a projection system comprising a laser light source; and a scanning mirror arrangement for receiving the light radiated by the laser light source, and for reflecting the received light to a wavelength conversion element to project the second image. In the method the second image is streamed to the projection controller as an image pixel stream without first saving it in a memory.

Devices and methods are described herein that use birefringent elements to reduce speckle. The birefringent elements are angularly separate received laser light into two separated light beams, and then recombine the two angularly separated light beams. At least one scanning mirror is configured to reflect the recombined laser light beam, and a drive circuit is configured to provide an excitation signal to excite motion of the at least one scanning mirror. The angular separation of the light beams generates a relative delay between the two light beams, and this relative delay between light beams generates a temporal incoherence in the recombined light beams. This temporal incoherence can reduce speckle in the projected image.

A projection device comprising a MEMS mirror which oscillates about one or more oscillation axes to scan light from one or more lasers, across a display screen, to project pixels which define an image onto a display screen is disclosed. A method comprising selecting a laser class for the projection device; calculating relationship between maximum accessible emission limit and distance, for the selected laser class, for a predetermined number of black pixels in an image; determining the distance between a display screen and the projection device; and modifying a pixel stream which defines said image which is to be projected by the projection device, so that the pixel stream is provided with said predetermined number of black pixels is provided.

To display an image and the back side image in an overlapped state on a screen, with good visibility and see-through capability. The screen scanned with an image light from the projector has an optical layer and a plurality of control electrodes which are arranged side by side along the optical layer. The synchronous controller applies a voltage to the plurality of control electrodes, and, in a scanning period T of the image light, switches the optical state of the screen by the unit of the segmented region, between the visual state and the nonvisual state. The synchronous controller, in the period T, switches the optical state of a plurality of segmented regions 22 in synchronous with the scanning period of the image light, maintains the optical state of a projected region of the screen in the visual state by a voltage with two or more amplitudes.

An image projection device for displaying an image onto a remote surface. The image projection device employs a scanner to project image beams of visible light and tracer beams of light onto a remote surface to form a display of the image. The device also employs a light detector to sense at least the reflections of light from the tracer beam pulses incident on the remote surface. The device employs the sensed tracer beam light pulses to predict the trajectory of subsequent image beam light pulses and tracer beam light pulses that form a display of the image on the remote surface in a pseudo random pattern. The trajectory of the projected image beam light pulses can be predicted so that the image is displayed from a point of view that can be selected by, or automatically adjusted for, a viewer of the displayed image.

A projection device comprises a light source, a first attenuator and a second attenuator, a first driver, a second driver, a light receiving element, and a controller. The light source emits light. The first attenuator and the second attenuator attenuate intensity of the light from the light source. The first driver drives the first attenuator. The second driver drives the second attenuator. The light receiving element receives the light distributed by the second attenuator. The controller controls the second driver to control the distribution ratio of the light distributed to the light receiving element by the second attenuator according to control of transmissivity of light at the first attenuator by the first driver.

A head worn display system with at least one retinal display unit having a curved reflector positioned in front of one eye or both eyes of a wearer. The unit includes a first set of three modulated visible-light lasers co-aligned and adapted to provide a foveal laser beam with selectable color and a first scanner unit providing both horizontal and vertical scanning of the laser beam across a small portion of the curved reflector in directions so as to produce a reflection of the color laser beam through the pupil of the eye onto a portion of the retina large enough to encompass the fovea. The unit also includes a second set three modulated retinal visible-light lasers plus an infrared laser, all lasers being co-aligned and adapted to provide a color and infrared peripheral view laser beam, and a second scanner unit providing both horizontal and vertical scanning of the visible light and infrared laser beams across a portion of the curved reflector in directions so as to produce a reflection of the scanned color and infrared laser beams through the pupil of the eye onto a portion of retina corresponding to a field of view of at least 30 degrees×30 degrees.

According to an aspect, a light source device includes: a light emitting device that emits a light beam capable of being modulated; and a scanning device that deflects the light beam in a first direction and a second direction intersecting the first direction. The light beam has a light quantity varying region in which a light quantity decreases outward from a center of the light beam in at least one of the first direction or the second direction. The scanning device overlaps the light quantity varying regions of a plurality of the light beams with each other with respect to a scanning direction along directions in which the light quantities of the light beams decrease.

A display apparatus (1) of the present invention includes: a transparent screen (10) configured by a transmissive or reflective volume hologram; a first image projection section (50a) disposed on a first main surface (Sa) side of the transparent screen (10), and projecting first image light (La1) onto the first main surface (Sa); and a second image projection section (50b) disposed on a second main surface (Sb) side of the transparent screen (10), and projecting second image light (Lb1) onto the second main surface (Sb). The display apparatus (1) further includes: a first light-shielding section (40a) preventing external light from being directly incident on the first main surface (Sa) at least at same incident angle as the first image light (La1); and a second light-shielding section (30b) preventing external light from being directly incident on the second main surface (Sb) at least at same angle as the second image light (Lb1).