Various embodiments described herein relates to a lens cap, adapted to be mechanically engaged over a lens assembly of an optical projector. The lens cap, as described herein, is adapted for vignetting a light pattern projected by the optical projector. The lens cap includes a front surface and a back surface, where on at least a portion of the front surface, an elliptically shaped aperture is defined. In this aspect, the elliptically shaped aperture is chamfered towards its peripheral ends, as the elliptically shaped aperture extends out from the back surface of the lens cap towards the front surface of lens cap. Also, the elliptically shaped aperture is defined on the lens cap such that, a center axis of the aperture is offset to a central axis of the lens cap, so as to match an offset at which the light pattern is projected by the optical projector.

An autograph support device includes a supporting member that supports an image carrier having a planar image display surface such that the image display surface that displays a mirror image of an image displayed on a planar writing surface is located above the writing surface of a writing medium having the planar writing surface; and a half mirror that is disposed between the writing surface and the image display surface and has a mirror surface facing the image display surface . The image display surface and the writing surface are disposed at an equal optical distance from the mirror surface of the half mirror interposed therebetween. A writing surface lighting fixture that radiates light from the mirror surface side toward the writing surface side to illuminate the writing surface is provided on the writing surface side from the mirror surface.

A projection apparatus includes a plurality of two-fluid nozzles, a projection-apparatus-side-gas-flow-path, a gas valve, a projection-apparatus-side-liquid-flow-path, a liquid valve, a projector, a mist concentration measurer, and a controller. The controller starts and stops spraying of a mist by controlling the gas valve and the liquid valve on the basis of an image or a video projected onto a screen from the projector. The controller receives a signal indicating a mist concentration from the mist concentration measurer, starts and stops spraying of the mist by controlling the gas valve and the liquid valve on the basis of the received signal, and thus controls the mist concentration.

Various embodiments described herein relates to a lens cap, adapted to be mechanically engaged over a lens assembly of an optical projector. The lens cap, as described herein, is adapted for vignetting a light pattern projected by the optical projector. The lens cap includes a front surface and a back surface, where on at least a portion of the front surface, an elliptically shaped aperture is defined. In this aspect, the elliptically shaped aperture is chamfered towards its peripheral ends, as the elliptically shaped aperture extends out from the back surface of the lens cap towards the front surface of lens cap. Also, the elliptically shaped aperture is defined on the lens cap such that, a center axis of the aperture is offset to a central axis of the lens cap, so as to match an offset at which the light pattern is projected by the optical projector.

Various embodiments described herein relates to a lens cap, adapted to be mechanically engaged over a lens assembly of an optical projector. The lens cap, as described herein, is adapted for vignetting a light pattern projected by the optical projector. The lens cap includes a front surface and a back surface, where on at least a portion of the front surface, an elliptically shaped aperture is defined. In this aspect, the elliptically shaped aperture is chamfered towards its peripheral ends, as the elliptically shaped aperture extends out from the back surface of the lens cap towards the front surface of lens cap. Also, the elliptically shaped aperture is defined on the lens cap such that, a center axis of the aperture is offset to a central axis of the lens cap, so as to match an offset at which the light pattern is projected by the optical projector.

A projection apparatus includes a plurality of two-fluid nozzles, a projection-apparatus-side-gas-flow-path, a gas valve, a projection-apparatus-side-liquid-flow-path, a liquid valve, a projector, a mist concentration measurer, and a controller. The controller starts and stops spraying of a mist by controlling the gas valve and the liquid valve on the basis of an image or a video projected onto a screen from the projector. The controller receives a signal indicating a mist concentration from the mist concentration measurer, starts and stops spraying of the mist by controlling the gas valve and the liquid valve on the basis of the received signal, and thus controls the mist concentration.

What is shown is a projection device having at least one light source and an array of optical channels. Each channel includes a first refractive optical free-form surface and a second refractive optical free-form surface and projection optics. The first and second refractive optical free-form surfaces are arranged between the light source and the projection optics and cause Khler illumination of the projection optics by an object light pattern, resulting in the image to be projected on an image surface of the projection optics, wherein images of the array of optical channels superimpose one another.

What is shown is a projection device having at least one light source and an array of optical channels. Each channel includes a first refractive optical free-form surface and a second refractive optical free-form surface and projection optics. The first and second refractive optical free-form surfaces are arranged between the light source and the projection optics and cause Khler illumination of the projection optics by an object light pattern, resulting in the image to be projected on an image surface of the projection optics, wherein images of the array of optical channels superimpose one another.

Dual and multi-modulator projector display systems and techniques are disclosed. In one embodiment, a projector display system comprises a light source; a controller, a first modulator, receiving light from the light source and rendering a halftone image of said the input image; a blurring optical system that blurs said halftone image with a Point Spread Function (PSF); and a second modulator receiving the blurred halftone image and rendering a pulse width modulated image which may be projected to form the desired screen image. Systems and techniques for forming a binary halftone image from input image, correcting for misalignment between the first and second modulators and calibrating the projector systeme.g. over timefor continuous image improvement are also disclosed.

The projection method obtains a circular-screen projection surface by dividing a visual platform to be projected, arranges each optical machine to be arranged according to maximum optical path distance information that each optical machine to be arranged projects an image onto each circular-screen projection surface to obtain a first projection coverage range, and adjusts the first projection coverage range according to setting parameters corresponding to each optical machine to be arranged and in accordance with a preset projection surface to obtain a second projection coverage range. The projection method calculates geometric parameters and the second projection coverage range of each optical machine to be arranged to obtain a spatial position and a rotation angle range of each optical machine to be arranged.