Patent Application
20070121084
1. Field of the Invention
The present invention relates to a projector, and more particularly, to a projector with a plurality of light sources.
2. Description of the Prior Art
With the progress of optics, projectors have found broad use in many applications. Generally speaking, projected light intensity is usually an important factor while designing a projector, as the projection quality improves with greater intensity of the projected light.
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Because the projector 10 includes only one bulb 30 as a lighting device to provide light to the projector 10, the power of the bulb 30 should be raised when enhancing the brightness of the projection image of the projector 10. However, this method of enhancing the brightness of the projection image of the projector 10 is improper. For example, when the power of the bulb 30 is raised, the waste heat of the bulb 30 increases correspondingly, increasing the operational temperature of the projector 10. Further, if the bulb 30 becomes too hot, the bulb 30 could burn out.
It is therefore a primary objective of the claimed invention to provide a projector with a plurality of light sources for solving the above-mentioned problem.
According to the claimed invention, a projector includes a housing, a first light source installed inside the housing for generating light beams, a second light source installed inside the housing for generating light beams, a first refractive element installed inside the housing for refracting the light beams generated by the first light source, a second refractive element installed inside the housing for refracting the light beams generated by the second light source to a direction parallel to a direction of the light beams refracted by the first refractive element substantially, a light pipe installed inside the housing for uniformizing light beams from the first refractive element and the second refractive element, and an image device installed inside the housing for processing the uniformized light from the light pipe and for projecting the processed light to form an image.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.
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The projector 50 further includes a focusing lens assembly 74 for focusing the condensed beams 71a, 71b from the first refractive element 70 and the second refractive element 72, and a color wheel 76 for filtering a light beam 78 via different filters to output red, green, and blue beams by turning. The focusing lens assembly 74 focuses the light beam 78 to an entrance of a light pipe 80. The light pipe 80 can uniformize the light beam 78 to output a uniformized beam 82. The projector 50 further includes an image device 84 for processing the uniformized beam 82 to modulate an image into the uniformized beam 82 to form an image beam 86. The image beam 86 is projected to a screen 90 to form a projection image.
The optical paths of the light from the first light source 54 and the second light source 68 to the screen 90 are described in detail as follows. First the light devices 56a, 56b are positioned on the focuses of the parabolic mirrors 62a, 62b respectively, so the light emitted from the light devices 56a, 56b is reflected as two parallel beams 92a, 92b by the parabolic mirrors 62a, 62b. The positive lenses 64a, 64b can refract and condense the parallel beams 92a, 92b, and then the negative lenses 66a, 66b can refract the light refracted by the positive lenses 64a, 64b as the light beams 60a, 60b. That is, the combination of the positive lenses 64a, 64b and the negative lenses 66a, 66b can condense light so that the light can be condensed to emit to the first refractive element 70 and the second refractive element 72. Then the first refractive element 70 and the second refractive element 72 deflect the light beams 60a, 60b to form the condensed beams 71a, 71b. The focusing lens assembly 74 focuses the condensed beams 71a, 71b to form the light beam 78. The color wheel 76 filters the light beam 78 via different filters to output red, green, and blue beams by turning. The focusing lens assembly 74 focuses the light beam 78 to the entrance of the light pipe 80. The light pipe 80 uniformizes the light beam 78 to output the uniformized beam 82. At last the image device 84 processes the uniformized beam 82 to modulate an image into the uniformized beam 82 to form the image beam 86. The image beam 86 is projected to the screen 90 to form a projection image.
The first refractive element 70 and the second refractive element 72 can change the optical paths of the light generated by the first light source 54 and the second light source 68 so as to condense the light emitted from the first light source 54 and the second light source 68. The light from the light source can be condensed to output to the lens of the projector 50 so as to enhance the brightness and uniformity of the projection image of the projector 50. In addition, the distance between the first light source 54 and the second light source 68 can be increased so as to prevent the concentrated heat generated by the light device 56a, 56b because the first refractive element 70 and the second refractive element 72 can focus the light emitted from the first light source 54 and the second light source 68 to the focusing lens assembly 74.
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The light devices 56a, 56b are positioned on the focuses of the ellipsoid mirrors 112a, 112b respectively, so the light emitted from the light devices 56a, 56b is reflected as two condensed beams 142a, 142b by the ellipsoid mirrors 112a, 112b. The negative lenses 116a, 116b can refract the condensed beams 142a, 142b as the light beams 110a, 110b. That is, the combination of the ellipsoid mirrors 112a, 112b and the negative lenses 116a, 116b can condense and parallelize light so that the light can be condensed to emit to the first refractive element 70 and the second refractive element 72. Then the first refractive element 70 and the second refractive element 72 deflect the light beams 110a, 110b to form the condensed beams 121a, 121b. The focusing lens assembly 74 focuses the condensed beams 121a, 121b to form the light beam 128. The color wheel 76 filters the light beam 128 via different filters to output red, green, and blue beams by turning. The focusing lens assembly 74 focuses the light beam 128 to the entrance of the light pipe 80. The light pipe 80 uniformizes the light beam 128 to output the uniformized beam 132. At last the image device 84 processes the uniformized beam 132 to modulate an image into the uniformized beam 132 to form the image beam 136. The image beam 136 is projected to the screen 90 to form a projection image.
In contrast to the conventional projector with one light device, the projector according to the present invention includes a plurality of light sources so as to enhance the brightness of the projection image. In addition, the refractive elements can condense the light generated by the light sources to form a condensed beam so as to concentrate the light to output to the lens of the projector, increasing light efficiency and uniformity of the light sources. In addition, the distance between the light sources can be increased so as to prevent the concentrated heat generated by the light sources.
Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 094141723 | Nov 2005 | TW | national |
