Source Projector Research Articles

Retro-reflection based projection 3D display with low crosstalk

Retro-reflection based projection 3D display with low crosstalk is proposed. The 3D display consists of a retro-reflective sheet, an image projector array, a vertical scattering layer, and two optical noise sources projectors. The image projector array is used to provide parallax images. The retro-reflective sheet is used to reflect parallax images to different horizontal viewpoints to form 3D images. The vertical scattering layer is used to scatter the reflected light in the vertical directions, and form viewing areas in the vertical projection area of each corresponding projector. The optical noise source projector provides salt and pepper noise to reduce crosstalk. A prototype of the proposed 3D display is developed, and the experiment results agree well with the theory.

A Novel Eye-Tracking Device Designed with a Head Gesture Control Module

In this paper a novel eye-tracking device designed which uses tiny CCD cameras to capture the eye image from the screen with the help of a video capture card. In the head gesture control mode, a light source projector is turned on and the CCD camera detects the position of the light source. The

10. SFPM workgroup report: “New techniques and quality assurance in brachytherapy”

Introduction Brachytherapy is a well-known treatment technique which delivers a high dose to a tumorous volume yet reducing irradiation for healthy surrounding tissue. Recent developments regarding the use of imaging highlighted the necessity to update and to complete the SFPM n°11 report of 1995 which used to be only about Iridium 192 high dose rate technique. This new report deals with techniques associated to a source projector for any dose rate (high dose rate HDR or pulsed PDR) and permanent Iodine 125 implants. Methods Propositions are based on tests proposed by the SFPM, IAEA, GEC-ESTRO, AAPM, constructor guidelines, a recent bibliographic study and French users experience. Results The report deals with: • Source calibration presenting iridium 192 (most commonly used), Iodine 125 (non-available in French primary laboratory), Cobalt 60 ( still in development) • Different kinds of imaging used for implantation or planning: ultrasound (US), scan (CT), MRI. More particularly, specific tests concerning US are presented due to their use for needles, applicators or sources implantation. • Treatment planning: proposed tests concern mainly algorithms based on TG43 formalism but also new algorithms. Tests are divided into three groups: generic tests common to all techniques, specific tests dealing with treatments delivered by source projectors (HDR or PDR), specific tests concerning permanent implants. • Quality assurance of the source projector is detailed according to HDR/PDR specificities for any radioelement used. Conclusions These guidelines allow defining necessary tests from the implementation of a new technique to the current use. Each test is associated to a frequency and a level of action yet remaining suitable as a matter of clinical routine.

高輝度・超短焦点レーザ光源プロジェクタの開発(映像情報機器および一般)

高輝度・超短焦点レーザ光源プロジェクタの開発(映像情報機器および一般)

A wave-making towing tank for underwater communication in a multi-path environment using time reversal method

A 4 m × 8 m × 176 m wave-making towing tank, which is original, used for resistance measurement for boats is a perfect test platform for underwater communication in a multi-path environment. The objective in the present study is to establish a process of underwater communication in a multi-path environment using the time reversal method. The source projector sends out a BPSK signal, while the signal is received and processed in order to restore the original signal at the source by time reversal method. The communication process is conducted via both numerical simulation and experiment for cases of underwater communication in a 4 m × 8 m × 176 m towing tank. It is found that TRM process reduces the error rate of the transmission significantly and improves the communication quality in multi-path environment. [Works are supported by National Science Council of Taiwan.]

高輝度・超短焦点レーザー光源プロジェクター

We have developed a laser light source projector with high brightness and ultra-short throw distance,

レーザ光源プロジェクタ向け高輝度・超短焦点投写光学系および色再現処理技術の開発

Our newly developed ultra-short throw distance laser light source projector is composed of triple rod illumination optics, mirror-lens hybrid ultra-wide angle projection optics and laser color processing. This projector has achieved the highest brightness of 7,000lm, the shortest throw distance of 60 cm at 100-inch image size and wider color gamut of 190% compared with sRGB by making full use of the advantages of laser such as high luminance, small etendue and high color purity. These specifications improve the visibility, convenience of installation and vividness of the image. In this paper, we describe our original developed technology such as the triple-rod illumination optical system, ultra-short projection optical system and laser color processing.

An eye-tracking and head-control system using movement increment-coordinate method

In this paper a novel design which combines an eye-tracking device with a head gesture control module is discussed. In the eye-tracking mode, the user wears goggles, and two tiny CCD cameras capture the eye image from the screen with the help of a video capture card. In the head gesture control mode, a light source projector is turned on, and the CCD camera detects the position of the light source. The locations of the spots on the screen and on the image pupil of the eye image are calculated, compared with the previous point and are subsequently mapped to the point on the screen. The movement increment-coordinate control is also discussed, which could improve the ease of use of the computer.

Encoding and Decoding of Color Information

Color information is recorded on a colorless substrate by having each color separation amplitude modulate a different spatial frequency carrier. This is accomplished in a single exposure using an appropriate color-encoding filter. The reconstruction of the color scene involves a point source projector with a color decoding mask. The light output of the projector, for sources of a given brightness, is shown to be proportional to the total number of lines in the encoding filter. The relatively, high efficiency of an encoded phase transparency is evaluated, and a decoding method is shown.