Projection optical system

Abstract

A projection optical system comprises a digital micro-mirror device; the digital micro-mirror device comprises a substrate with a plurality of external contacts, a plurality of micro-reflector devicesarranged on the substrate, and a plurality of lead wires for correspondingly and electrically connecting the external contacts with the micro-reflector devices. The optical system also comprises a light-blocking element arranged on the optical path of the digital micro-mirror device; and the light blocking element is arranged correspondingly to the lead wires and used to prevent the images generated by the lead wires being projected onto the projection image. The projection optical system prevents the incidence light irradiating the lead wires of the digital micro-mirror device through the light-blocking element, or blocks the stray light reflected by the lead wires of the digital micro-mirror device before the stray light is projected to the projection image, so as to avoid the images produced by the lead wires being projected onto the projection image, thereby improving the contrast of the projection image.

Description

technical field [0001] The invention relates to an optical system for a projector, in particular to a projection optical system capable of blocking stray light. Background technique [0002] Projectors are widely used as devices for personal computers and televisions that can enlarge images such as video and project them on a screen. During the use of the projector, users often require the projected image to have high contrast. Therefore, it is necessary to improve the optical system of the projector to increase the contrast of the projected image. [0003] Generally, a digital light processing (Digital Light Processing, hereinafter referred to as DLP) projector has a digital micromirror device (Digital Mirror Device, hereinafter referred to as DMD) for changing the reflection angle of incident light. The digital micromirror device is composed of multiple micromirror devices. like figure 1 As shown, the digital micromirror device includes a substrate 10 with a plurality o...

AI Technical Summary

Problems solved by technology

[0004] The above-mentioned digital micromirror device of the projector has wires 121 electrically connected to the external contact point 101 of each micromirror device and the substrate 10, and due to manufacturing process and cost considerations, the wires 121 are exposed on the surface of the substrate 10, so that when the digital micromirror device When the mirror device receives incident light, the incident light will also shine on the wire 121, and the wire 121 will reflect stray light, and the general projector does not eliminate the stray light, so that the image produced by the stray light Included in the light path of the projector and projected onto the projected image, which reduces the contrast of the projected image

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