Light-emitting diode (LED) illuminating light path for projector

Abstract

The invention relates to a light-emitting diode (LED) illuminating light path for a projector. The illuminating light path comprises a first LED light source, a second LED light source, a third LED light source, a first lens group, a second lens group, a third lens group, a first dichroic mirror, a second dichroic mirror and a fourth lens group, wherein the first, second and third lens groups are used for converging the first, second and third LED light sources into near parallel light; the first dichroic mirror is used for combining the near parallel light of the first and second lens groups; the second dichroic mirror is used for combining the combined light obtained by the first dichroic mirror with the parallel light of the third lens group; the fourth lens group is used for converging the combined light obtained by the second dichroic mirror into light spots; moreover, the light paths of the first lens group and the second lens group have the same length and adopt the same lens group; the light path of the third lens group is shorter than that of the first or second lens group; and the light spots obtained by converging the parallel light emitted from the first, second and third lens groups through the fourth lens group have high consistency. The light spots obtained by light combination have high color uniformity, so that the color uniformity of the projector is improved to a certain extent.

Description

technical field [0001] The invention relates to an LED lighting light path for a projector. Background technique [0002] With the improvement of actual demand, higher requirements are put forward for projectors, focusing on brightness improvement, environmental protection, price reduction, etc., and the emergence of LEDs better adapts to this trend. Because LED has the characteristics of sensitive response, high luminous efficiency, longer service life, higher color saturation, and no toxic substances, it is widely used in backlight, display, lighting and other fields. At present, projectors have also begun to use LEDs as lighting sources, but compared with traditional bulbs, there is still a gap in brightness to some extent, and the light distribution angle of LEDs is relatively large, which affects the performance of projectors. Therefore, developing an LED lighting light path suitable for projectors has become an urgent problem to be solved. [0003] In order to obtain...

AI Technical Summary

Problems solved by technology

However, in this scheme, since the optical path lengths of the two color light sources are the same, while the optical path length of the other color light source is relatively short, and finally the three color lights are concentrated by the same lens group, so the matching degree of the optical system is poor, and the single The light spots of the color light sources are inconsistent, resulting in poor color uniformity of the final lighting spots after light combination

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