Abstract:
The present invention relates to a color wheel unit comprising a color wheel having a rotatable filter supporter and a plurality of color filters radially attached to the filter supporter; a color wheel supporter for rotatably supporting the color wheel; a projection provided in at least one of the color filters; and a projection holder for engagement with the projection and provided in at least one of the color filter adjacent to the color filter having the projection and the filter supporter for preventing the color filter from a radial outward breakaway. Thus, the present invention provides a color wheel unit and an optical engine with the same, in which a color filter is stably mounted.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application claims the benefit under 35 U.S.C. § 119(a) of Korean Patent Application No. 2004-0108836, filed on Dec. 20, 2004, in the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a color wheel unit and an optical engine having the same. More particularly, the present invention relates to a color wheel unit and an optical engine having the same, which has an improved structure of a color filter provided in the color wheel unit. 
   2. Description of the Related Art 
   In general, an optical engine is provided in a display apparatus such as a projection television, a projector, or the like, and projects an image on a screen. Such an optical engine is classified into a cathode ray tube (CRT) type, a liquid crystal display (LCD) type, a digital light processing (DLP) type, and the like according to display devices for displaying processed video data. 
   In particular, the DLP type optical engine comprises a color wheel. Here, the color wheel comprises a plurality of color filters for selectively filtering red (R), green (G) or blue (B) out of white light emitted from a light source. 
   Here, the color wheel is rotatable for allowing the light emitted from the light source to selectively pass through one of the color filters. 
     FIG. 1  is a perspective view of a conventional color wheel. As shown therein, a conventional color wheel  110  comprises a plurality of color filters  111  arranged like a disk shape and a filter supporter  121  supporting the plurality of color filters  111 . 
   Each color filter  111  comprises a filter  115  having a fan shape for filtering the light emitted from the light source and a supporter adhering portion  117  disposed radially inside the filter  115  and attached to the filter supporter  121  by an adhesive. 
   The filter supporter  121  is rotatably coupled with a color wheel supporter (not shown), thereby rotating the color filter  111 . 
   In the conventional color wheel  110 , the plurality of color filters  111  are coupled to the filter supporter  121  and the filter supporter  121  is rotatably coupled to the color wheel supporter (not shown). Thus, the plurality of color filters  111  can rotate. 
   However, in the conventional color wheel, the supporter adhering portion of the color filter is attached to the filter supporter with the adhesive, so that the color filter may be detached from the filter supporter by a centrifugal force at high rotation speed, or by same other force. 
   Accordingly, a need exists for a color wheel unit with an improved structure capable of attaching a color filter to a filter supporter. 
   SUMMARY OF THE INVENTION 
   Accordingly, an aspect of the present invention is to provide a color wheel unit and an optical engine having the same, in which a color filter is stably mounted. 
   Additional aspects and/or advantages of embodiments of the present invention will be described in part in the following description and, in part, will be obvious from the description, or may be obviously learned by practice of the present invention. 
   The foregoing and/or other aspects of the present invention are also achieved by providing a color wheel unit comprising a color wheel including a rotatable filter supporter and a plurality of color filters radially attached to the filter supporter, a color wheel supporter rotatably supporting the color wheel, a projection provided in at least one of the color filters, and a projection holder engaged with the projection and provided in at least one of the color filter adjacent to the color filter having the projection and the filter supporter for preventing the color filter from radially breaking away. 
   According to another aspect of the present invention, the projection protrudes from at least one of the color filters toward the adjacent color filter. 
   According to another aspect of the present invention, the color filter comprises a supporter coupling portion attached to the filter supporter, a filtering portion outwardly extending from the supporter coupling portion, a projection protruded from a surface of the supporter coupling portion toward the filter supporter, and a projection holder formed on the filter supporter and accommodating the projection. 
   According to another aspect of the present invention, the color filters comprise at least one narrow color filter narrower than the other color filters and a projection provided in the narrow color filter. 
   Other aspects of the present invention are also achieved by providing an optical engine for a DLP type, comprising a light source to emit light, a color wheel unit selectively filtering light emitted from the light source, a DLP panel forming an image by adjusting a reflecting angle of the light passed through the color wheel unit, and a projecting lens for projecting the image formed on the DLP panel to a screen. 
   Other objects, advantages and salient features of the present invention will become apparent from the following detailed description of the embodiments, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a conventional color wheel; 
       FIG. 2  is an exploded perspective view of a color wheel unit according to an exemplary embodiment of the present invention; 
       FIG. 3  is an exploded perspective view of a color filter provided in the color wheel unit of  FIG. 2 ; 
       FIG. 4  is an exploded perspective view of another color filter provided in the color wheel unit according to an exemplary embodiment of the present invention; 
       FIG. 5  is an exploded perspective view of a color filter provided in a color wheel unit according to an exemplary embodiment of the present invention; and 
       FIG. 6  is an exploded perspective view of an optical engine according to an exemplary embodiment of the present invention. 
   

   Throughout the drawings, like reference numerals will be understood to refer to like parts, components and structures. 
   DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
   Reference will now be made in detail to exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings. 
   As shown in  FIGS. 2 through 4 , a color wheel unit  1  according to an exemplary embodiment of the present invention comprises a color wheel  10  for selectively filtering red (R), green (G) or blue (B) out of light emitted from a light source and a color wheel supporter  30  for rotatably supporting the color wheel  10 . According to an exemplary embodiment of the present invention, the color wheel unit  1  further comprises a motor body  25  coupled to a filter supporter  21  of the color wheel  10  for rotating integrally with the filter supporter  21  and a motor shaft  27  coupled to the color wheel supporter  30  for allowing the motor body  25  to rotate. According to an exemplary embodiment of the present invention, the color wheel unit  1  further comprises a sensor  31  provided in the color wheel supporter  30  and an index part  29  either provided in a predetermined region of the color wheel  10  or the motor body  25  for irregularly reflecting the light emitted from the sensor  31 . 
   The color wheel  10  has a disk shape and is generally mounted in a DLP type optical engine. The color wheel  10  comprises the filter supporter  21  rotatably coupled to the color wheel supporter  30  and a plurality of color filters  11  radially attached to the filter supporter  21 . One of the color filters  11  is formed with at least one projection  18  protruding toward at least one adjacent other color filter  11 . The adjacent other color filter  11  is formed with a projection holder  19  to be engaged with the projection  18 , for thereby preventing the color filter  11  from radially breaking away. 
   The plurality of color filters  11  selectively filters the red (R), the green (G) and the blue (B) out of the light emitted from the light source, respectively. Each color filter  11  has a fan shape and is coupled to the filter supporter  21 . Further, each color filter  11  comprises a supporter coupling portion  17  attached to the filter supporter  21  and a filtering portion  15  outwardly extending from the supporter coupling portion  17 . Here, at least one of the color filters  11  is a narrow color filter  13  narrower than the other color filters  11 . That is, the plurality of color filters  11  comprises the narrow color filter  13  and regular color filters  14  wider than the narrow color filter  13 . 
   The supporter coupling portion  17  is placed in an inner portion of the color filter  11  and coupled to a filter coupling portion  23  of the filter supporter  21  by an adhesive. Alternatively, the connection between the supporter coupling portion  17  and the filter coupling portion  23  is not limited to the adhesive, and may be achieved by various methods. 
   The filtering portion  15  is a region for substantially filtering the red (R), the green (G) and the blue (B) out of the light emitted from the light source. 
   The narrow color filter  13  is narrower than the regular color filter  14  and thus has a light passing time less than the regular color filter  14 . Here, the narrow color filter  13  has a narrow angular width as compared with the regular color filter  14 . Consequentially, the supporter coupling portion  17  of the narrow color filter  13  to contact the filter supporter  21  is also narrower than the regular color filters  14 . Because the supporter coupling portion  17  of the narrow color filter  13  is narrower than the regular color filters  14 , adhesive force between the narrow color filter  13  and the filter supporter  21  is weaker than between the regular color filter  14  and the filter supporter  21 . In general, the narrow color filter  13  passes black, dark green, or the like for thereby clearing light and darkness of a dark image. Alternatively, the narrow color filter  13  is not limited to the black, the dark green, or the like, and may pass light of various colors. 
   According to an exemplary embodiment of the present invention, the projection  18  protrudes from the narrow color, filter  13  toward adjacent regular color filters  14 . Further, the projections  18  are provided in opposite sides of the narrow color filter  13 , respectively. Preferably, the projection  18  is placed in the supporter coupling portion  17  of the narrow color filter  13 , but may be placed in the filtering portion  15  of the narrow color filter  13 . Referring to  FIG. 3 , a pair of projections  18  protrudes from an inner end of the supporter coupling portion  17  of the narrow color filter  13  toward the adjacent regular color filter  14 . Referring to  FIG. 4 , a pair of projections  18   a  in a color wheel  10   a  can protrude from the opposite sides of the supporter coupling portion  17  of the narrow color filter  13  toward the adjacent regular color filter  14 . Alternatively, the projections  18  and  18   a  are not limited to the narrow color filter  13 , and may be placed in the regular color filter  14 . 
   The projection holder  19  is placed in the regular color filter  14  adjacent to the narrow color filter  13  and engaged with the projection  18 . Consequentially, the projection  18  is prevented from radially breaking away from the filter supporter  21 . As shown in  FIG. 3 , the projection holder  19  is formed by cutting an inner end of the regular color filter  14  adjacent to the narrow color filter  13  in order to hold the projection  18  formed in the inner end of the supporter coupling portion  17  of the narrow color filter  13 . Alternatively, as shown in  FIG. 4 , a projection holder  19   a  may be formed by recessing a lateral side of the regular color filter  14  adjacent to the narrow color filter  13  in order to accommodate the projection  18   a  formed in the opposite sides of the supporter coupling portion  17  of the narrow color filter  13 . 
   The filter supporter  21  is shaped like a circular plate. Further, the filter supporter  21  comprises the filter coupling portion  23  to which the supporter coupling portion  17  of the color filter  11  is attached and a motor body coupling portion  24  placed in the center of the filter supporter  21  and coupled with the motor body  25 . Thus, the plurality of color filters  11  are radially attached to the filter supporting portion  23  of the filter supporter  21 . The filter supporter  21  is integrally coupled with the motor body  25  and rotates integrally with the motor body  25 . Here, the filter supporter  21  is made of aluminum. Alternatively, the filter supporter  21  can be made of any suitable material so long as it can support the plurality of color filters  11 . 
   The motor body  25  comprises an outer side rotatably coupled to the filter supporter  21  for rotating integrally with the filter supporter  21  and an inner side coupled to the motor shaft  27  and supported by the color wheel supporter  30 . Alternatively, the motor body  25  may be supported by the color wheel supporter  30 , and the motor shaft  27  may be coupled to the filter supporter  21  and allowing the filter supporter  21  to rotate. The outer circumference of the motor body  25  has a cylindrical shape and is made of a material capable of reflecting light from the sensor  31  to the sensor  31 . For example, the outer circumference of the motor body  25  is made of aluminum. 
   The color wheel supporter  30  is formed with a shaft coupling portion  33  to be coupled with the motor shaft  27  for rotatably supporting the color wheel unit  1 . Alternatively, when the motor shaft  27  is coupled with the filter supporter  21 , the color wheel supporter  30  may be coupled with the motor body  25  for rotatably supporting the color wheel unit  1 . 
   The sensor  31  is provided in the color wheel supporter  30  and emits light to the index part  29 . The index part  29  is provided on the outer circumference of the motor body  25  for irregularly reflecting the light emitted from the sensor  31 . Alternatively, the index part  29  may be provided in the filter supporter  21 . 
   With this configuration, the color wheel  10  of the color wheel unit  1  according to an exemplary embodiment of the present invention is assembled as follows. 
   First, the adhesive is applied onto the filter coupling portion  23  of the filter supporter  21 , and then the plurality of color filters  11  are attached to the filter coupling portion  23 . At this time, the projection  18  of the narrow color filter  13  is engaged with the projection holder  19  of the regular color filter  14  adjacent to the narrow color filter  13 . Thus, the color wheel  10  is stably supported by the color wheel supporter  30 , so that the narrow color filter  13  is prevented from radially breaking away due to the centrifugal force even though the color wheel unit  1  rotates at high speed. 
   In the color wheel unit according to an exemplary embodiment of the present invention, at least one of the color filters supported by the filter supporter is provided with the projection, and the adjacent color filter is provided with the projection holder to which the projection engaged in a direction lateral to the radial direction of the filter supporter, so that the color filter is stably mounted even though the color wheel rotates at high speed. 
     FIG. 5  is an exploded perspective view of a color filter provided in a color wheel unit according to an exemplary embodiment of the present invention. As shown therein, in a color wheel  10   b  according to an exemplary embodiment of the present invention, a projection  18   b  is formed on a surface of the supporter coupling portion  17  of at least one color filter  14 , and a projection holder  19   b  is formed on the filter supporter  21  and accommodates the projection  18   b.    
   According to an exemplary embodiment of the present invention, the pair of projections  18   b  is formed on the surface of the supporter coupling portion  17  of the narrow color filter  13 . Alternatively, a single projection, or three, or more projections may be formed on the surface of the supporter coupling portion  17  of the narrow color filter  13 . Further, the projection may be formed on a surface of the supporter coupling portion  17  of the regular color filter  14 . 
   The projection holder  19   b  is recessed on the filter coupling portion  23  of the filter supporter  21  and accommodates the projection  18   b  in order to prevent the narrow color filter  13  from radially breaking away due to a centrifugal force when the color wheel  10   b  rotates at the high speed. 
   In the color wheel unit according to an exemplary embodiment of the present invention, at least one of the color filters supported by the filter supporter is provided with the projection, and the filter supporter is provided with the projection holder to which the projection engaged in a direction lateral to the radial direction of the filter supporter, so that the color filter is stably mounted even though the color wheel rotates at high speed. 
     FIG. 6  is an exploded perspective view of an optical engine according to an exemplary embodiment of the present invention. As shown therein, an optical engine  50  according to an exemplary embodiment of the present invention comprises a light source  51  emitting light in a DLP manner, a color wheel unit  1  for selectively filtering the light emitted from the light source  51 , a DLP panel  55  for forming an image by adjusting a reflection angle of the light passed through the color wheel unit  1 , and a projecting lens  57  for projecting the image formed on the DLP panel  55  to a screen (not shown). According to an exemplary embodiment of the present invention, the optical engine  50  further comprises an optical unit  53  interposed between the light source  51  and the color wheel unit  1  or between the color wheel unit  1  and the DLP panel  55  for uniformizing the light and a cooling fan  59  for cooling the light source  51 , the color wheel unit  1  or the like, which radiate heat of high temperature. 
   The light source  51  includes an arc-discharging lamp such as a mercury lamp, a metal halide lamp, a xenon lamp, or the like. When the light source  51  emits light, heat of high temperature is radiated. 
   With this configuration, the optical engine  50  according to an exemplary embodiment of the present invention is mounted to a projection television or a projector for projecting an image on the screen. 
   Thus, the optical engine according to an exemplary embodiment of the present invention comprises the color wheel unit, of which the projection is provided in at least one of the color filters, and the projection holder engaged with the projection so as to prevent the color filters from radially breaking away. Accordingly the color filter is stably mounted even though the color wheel rotates at high speed. 
   As described above, the present invention provides a color wheel unit and an optical engine with the same in which a color filter is prevented from radially breaking away even though a color wheel rotates at high speed, thereby stably mounted. 
   Although exemplary embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.