Projector with enhanced security camcorder defeat

Abstract

A projector (10) with enhanced security camcorder defeat including a copy protection illumination system (1) for illuminating a spatial light modulator (30) comprises: a polychromatic light source (20); uniformizing optics (22) for homogenizing light from the polychromatic light source to provide a uniform illumination field; relay optics; dichroic optics; an interference modulation element (5) located at a plane in an optical path located between the polychromatic light source and the spatial light modulator; and a detection means for determining the absence of the interference modulation element.

Description

technical field [0001] The present invention relates generally to a projection apparatus that utilizes a spatial light modulator to form a color image from digital data, and more particularly to the anti-counterfeiting capability that the projection apparatus enables to achieve while maintaining the source illumination and the telecentric optical path of the modulated light . Background technique [0002] In order to be considered a suitable replacement for conventional film projectors, a digital projection system must meet the required requirements with respect to image quality. This is especially true for multicolor film projection systems. In order to provide a competing alternative to conventional film-quality projection , digital projectors must meet high performance standards to provide high resolution, wide color gamut, high brightness, and a contrast ratio of more than 1000:1 frame-to-plane sequence. In addition to these requirements, some steps need to be taken to e...

AI Technical Summary

Problems solved by technology

[0009] The above example for still-frame images illustrates a key issue: invisible watermarks recognize but do not detrimentally affect the quality of legitimate copies, whereas visible watermarks can be distracting and degrade the viewing experience for the intended audience. For video and film images That said, there are other problems with conventional watermarking. For example, U.S. Patent No. 5,960,081 (Vynne et al.) discloses the use of motion vector data to add covert watermarking to MPEG data. This method identifies and authenticates the original compressed data stream, However, it will not provide identification of movies reproduced using camcorders. Other patents, such as U.S. Patent Nos. The watermark is added directly to the discrete cosine transform (DCT) coefficients of the MPEG-compressed video signal. If the watermarked image is sequentially recompressed using a lossy compression method (for example, as used in camcorders), or modified by some other image processing operation Watermarked images, the watermark will no longer be detectable.

[0022] ・ Illegal copying of viewing images worsened

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