Patent Application
20090310090
1. Technical Field
The invention relates to color wheels and, particularly, to a color wheel combining color filter segments adhesively thereof and a projector having the same.
2. Description of the Related Art
A color wheel for use in projectors typically includes a carrier and color filter segments. The color filter segments are combined on the carrier adhesively. Color wheels typically include a cover attached to the combined color filter segments configured for blocking light from directly impinging on the adhesive. On the other hand, the diameter of the cover is significantly smaller than that of the color filter segments to leave a light transmissive region on the combined color filter segments for filtering light. As a consequence, a small amount of light can still reach the adhesive via reflections in the combined color filter segments, thereby deteriorating the adhesive.
Therefore, it is desirable to provide a color wheel and a projector that can overcome the above-mentioned problem.
In an exemplary embodiment, a color wheel includes a motor, a carrier, a number of color filter segments, a layer of adhesive, and an ultraviolet (UV) filter. The motor includes a rotor. The carrier is fixed to the rotor. The color filter segments are adhesively attached to the carrier. The ultraviolet filter is placed so that the adhesive is interposed between the UV filter and the carrier. The ultraviolet filter is substantially similar to the color filter segments in shape and size.
Embodiments of the present color wheel and projector will now be described in detail with references to the accompanying drawings.
Referring to
The light source 110, such as a high pressure mercury lamp, a metal halide lamp, or a xenon lamp, is configured for generating white light. The condensing lens 120 is configured for condensing the generated white light from the light source 110.
The color wheel 130 is configured for dispersing the condensed white light impinging thereon into three colored lights, such as red (R), green (G), and blue (B) lights. The color wheel 130 includes a motor 131, a carrier 132, a layer of adhesive 133, a number of color filter segments 135, and an ultraviolet filter 134. The motor 131 includes a rotor 136. The carrier 132 is fixed to the rotor 136 via adhesive or threads. The color filter segments 135 are annularly arranged and attached to the carrier 132 via the adhesive 133. In this embodiment, the UV filter 134 is a film formed on a first surface 137 of the arranged color filter segments 135 facing the adhesive 133. Specifically, the carrier 132 is disk-shaped and has an attachable surface 138 facing away from the motor 131. The color filter segments 135 may include three color filter segments 135 such as R, G, and B color filters, and are coaxially attached to the attachable surface 138. Therefore, the color filter segments 135 are combined on the carrier 132 and form an annular transmissive region 139 being inserted in the light path of the condensed white light. When the rotor 136 rotates, the annular transmissive region 139 also rotates and disperses the condensed white light into color lights, e.g., R, G and B lights, in sequence. In this embodiment, the carrier 132 is a metal ring. The adhesive 133 is a hot and curable adhesive, such as UV curable adhesive.
The motor 131 is configured for driving the color filter segments 135 to rotate. In this embodiment, the rotor 136 is a rotating housing with a shaft coaxially protruding therefrom. In addition to the rotor 136, the motor 131 further includes electromagnetic members (not shown), e.g., ferromagnets coated to the inner surface of the rotating housing and windings fixedly received within the rotating housing for driving the rotor 136 to rotate when the windings are electrically powered.
When assembling the color wheel 130, the UV filter 134 is firstly formed on the color filter segments 135 via various deposition methods. Then, adhesive 133 is spread over the attachable surface 138. Next, the color filter segments 135 formed with the UV filter 134 are disposed on the adhesive 133 in an annular manner. Subsequently, the adhesive 133 is cured to fixedly combine the color filter segments 135 on the carrier 132. Finally, the combination of the carrier 132, the color filter segments 135 and the UV filter 134 is fixed to the rotor 136.
The DMD 140 is configured for modulating the color lights from the color wheel 130 into visual images according to input video signals. The projection lens 150 is configured for enlarging the visual images and presenting them on a screen 160.
The UV filter 134 of this embodiment can efficiently prevent light reflected from the color filter segments 135 from impinging the adhesive 133, thereby ensuring the quality and longevity of the adhesive 133.
Referring to
Referring
The UV filter is not limited to the described embodiments and can be any UV filter placed so that the adhesive 133 is interposed between the UV filter and the carrier 132 and is similar to the arranged color filter segments 135 in shape and size. For example, the UV filter 134 can be a film formed on the surface 138, or a transparent substrate formed with UV filter film and attached to the surface 137, 138.
It will be understood that the above particular embodiments and methods are shown and described by way of illustration only. The principles and the features of the present invention may be employed in various and numerous embodiments thereof without departing from the scope of the invention as claimed. The above-described embodiments illustrate the scope of the invention but do not restrict the scope of the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 200810302145.1 | Jun 2008 | CN | national |
