Abstract:
A projector device-of the present invention includes a light blocking mechanism for blocking leak light from a lamp unit. The light blocking mechanism includes a first light blocking member having a plurality of first light blocking plates arranged therein at certain pitches, and a second light blocking member having a plurality of second light blocking plates arranged therein at certain pitches. The first light blocking plates and the second light blocking plates each define a gap providing an air flow passage. A flat inclined part of each second light blocking plate extends in an inverted direction to a flat inclined part of each first light blocking plate, with a predetermined angle of inclination, so that the first light blocking plates and the second light blocking plates block the light emitted from the lamp unit toward a vent of a casing in all orientations.

Description:
[0001]    The priority application Number 2006-128732 upon which this patent application is based is hereby incorporated by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a projector device adapted to guide light from a light source to an optical system to generate images for magnification projection on a forward screen. 
         [0004]    2. Description of Related Art 
         [0005]    A projector device includes a casing containing an optical unit for generating images and a lamp unit as a light source for the optical unit. The lamp unit is air-cooled by cooling air, because the lamp unit generates heat when it emits light, and will have a shortened life if the temperature of the lamp unit exceeds a critical temperature. 
         [0006]      FIG. 15  shows a lamp unit  4  contained in a holder  71 . The holder  71  has air vents  72  for exhausting warm air that has cooled the lamp unit  4  inside the holder  71  outside the holder  71 . The casing has an exhaust vent for exhausting the warm air exhausted from the inside of the holder  71  outside. 
         [0007]    The air vents  72  of the holder  71  and the exhaust vent of the casing are located close to each other in order to quickly exhaust the warm air inside the holder  71  outside. In order to prevent light from the lamp unit  4  from leaking outside from the exhaust vent of the casing through the air vents  72  of the holder  71 , conventional projector devices employ light blocking plates  73 , as shown in  FIG. 13 , inclined relative to the opening plane of the air vents  72  of the holder  71  and arranged between the holder  71  and the casing, or, as shown in  FIG. 14 , a holder having air vents  72  with an inclined inner peripheral surface (see JP 2005-274730, A). 
         [0008]    However, the above arrangements cannot block outgoing beams from the lamp unit  4  indicated by dotted arrows in  FIG. 13  and  FIG. 14 , and cannot completely prevent the light of the lamp unit  4  from leaking from the exhaust vent of the casing. 
       SUMMARY OF THE INVENTION 
       [0009]    Accordingly, an object of the present invention is to provide a projector device that ensures that outgoing beams of the lamp unit can be prevented from leaking outside the casing through the vent of the casing. 
         [0010]    A projector device of the present invention includes a casing  1  containing a lamp unit  4  and an optical system for generating image light using the lamp unit  4  as a light source to project the generated image light toward a screen, the casing  1  having a wall surface provided with a vent opposed to the lamp unit  4 . 
         [0011]    The wall surface of the casing  1  opposed to the lamp unit  4  has a light blocking mechanism  9  arranged thereon covering the vent, the light blocking mechanism  9  including a first light blocking member  55  and a second light blocking member  6  arranged close to each other in the vent extending direction. 
         [0012]    The first light blocking member  55  has a plurality of first light blocking plates  56  arranged therein at certain pitches and extending in a same direction approximately perpendicular to the vent extending direction, each first light blocking plate  56  defining a gap providing an air flow passage. 
         [0013]    The second light blocking member  6  has a plurality of second light blocking plates  64  arranged therein at the same pitches as those of the first light blocking plates  56  and extending in the same direction as the first light blocking plates  56 , each second light blocking plate  64  defining a gap providing an air flow passage. Each first light blocking plate  56  includes a flat inclined part having a predetermined angle of inclination relative to the wall surface, while each second light blocking plate  64  includes a flat inclined part having a predetermined angle of inclination relative to the wall surface and extending in an inverted direction to the inclined part of each first light blocking plate  56 . The first light blocking plates  56  and the second light blocking plates  64  are arranged to provide a predetermined phase difference therebetween, so that the light blocking mechanism  9  blocks the light emitted from the lamp unit  4  toward the vent in all orientations. 
         [0014]    Specifically, the first light blocking plates  56  and the second light blocking plates  64  are each formed to have a length across the vent provided in the wall surface. The first light blocking plates  56  and the second light blocking plates  64  each include a flat parallel part extending from the corresponding inclined part and approximately parallel with the wall surface. 
         [0015]    More specifically, the first light blocking member  55  is provided on a holder  5  containing the lamp unit  4 , the holder  5  including a side wall  53  in the form of a frame having a central opening, the first light blocking plates  56  extending across the central opening of the side wall  53 , the second light blocking member  6  being held within a central opening  63  of a frame  60 , the second light blocking plates  64  extending across the central opening  63  of the frame  60 . 
         [0016]    Furthermore specifically, the first light blocking plates  56  each have side wall parts  59 ,  59  formed at opposite longitudinal ends thereof and projecting approximately perpendicularly from opposite end edges of the corresponding inclined part to the side wall  53  of the holder  5 , and the second light blocking plates  64  each have side wall parts  67 ,  67  formed at opposite longitudinal ends thereof and projecting approximately perpendicularly from opposite end edges of the corresponding inclined part to the frame  60 . This prevents the light from leaking from the opposite longitudinal ends of the first light blocking plates  56  and the second light blocking plates  64 . 
         [0017]    As described above, the projector device of the present invention ensures that outgoing beams from the lamp unit can be prevented from leaking outside through the exhaust vent of the casing. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]      FIG. 1  is a perspective view showing a liquid crystal projector device of the present invention as a whole; 
           [0019]      FIG. 2  is a back view of the liquid crystal projector device shown in  FIG. 1 ; 
           [0020]      FIG. 3  is a plan view showing an arrangement of a lamp unit and an optical unit mounted in the liquid crystal projector; 
           [0021]      FIG. 4  is a plan view showing an optical system of the lamp unit and the optical unit mounted in the liquid crystal projector; 
           [0022]      FIG. 5  is a side view of the lamp unit contained in an inner holder; 
           [0023]      FIG. 6  is a back view of the lamp unit contained in the inner holder; 
           [0024]      FIG. 7  is a perspective view showing the lamp unit, the inner holder, a light blocking member and an exhaust fan device as a whole; 
           [0025]      FIG. 8  is an exploded perspective view of the lamp unit, inner holder, light blocking member and exhaust fan device; 
           [0026]      FIG. 9  is a perspective view of the inner holder; 
           [0027]      FIG. 10  is a perspective view of the light blocking member; 
           [0028]      FIG. 11  is a back view of the exhaust fan device; 
           [0029]      FIG. 12  illustrates light paths in the light blocking mechanism; 
           [0030]      FIG. 13  illustrates light paths of a conventional liquid crystal projector device from the inside of a holder toward the outside of a casing; 
           [0031]      FIG. 14  illustrates light paths in another conventional liquid crystal projector device from the inside of a holder toward the outside of a casing; and 
           [0032]      FIG. 15  is a side view of a lamp unit contained in a holder in still another conventional liquid crystal projector device. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0033]    The present invention embodied in a liquid crystal projector device will be specifically described below with reference to the drawings. As shown in  FIG. 1 , the liquid crystal projector includes a flat casing  1  including a lower half case  11  and an upper half case  12 . The casing  1  has a front panel  13  provided with a projection window  14 . As shown in  FIG. 2 , a vent used as an exhaust vent  15  is provided in a rear panel  17 . 
         [0034]    Included inside the casing  1  are, as shown in  FIG. 3 , an optical unit  2  for generating color image light, and a lamp unit  4  providing a light source for the optical unit  2 . The lamp unit  4  is contained in an outer holder  7 . 
       Optical Unit 
       [0035]    As shown in  FIG. 4 , in the optical unit  2 , white light from the lamp unit  4  falls on a first field mirror  21 , and is reflected by the first field mirror  21  to fall on a first dichroic mirror  22 . The first dichroic mirror  22  reflects red light and green light, so that only blue light passes through the first dichroic mirror  22 . The blue light that has passed through the first dichroic mirror  22  falls on a second field mirror  23 , and is reflected by the second field mirror  23  to enter a color synthesizer  3 . 
         [0036]    The red and green light reflected by the first dichroic mirror  22  falls on a second dichroic mirror  27 . The second dichroic mirror  27  reflects the green light. The green light reflected by the second dichroic mirror  27  enters the color synthesizer  3 . 
         [0037]    The red light incident on the second dichroic mirror  27  passes through the second dichroic mirror  27 , and is reflected by a third field mirror  26  and a fourth field mirror  25  to enter the color synthesizer  3 . 
       Color Synthesizer 
       [0038]    The color synthesizer  3  includes a color synthesis prism  30 , a red image generating unit  31 , a green image generating unit  33  and a blue image generating unit  32 . The red image generating unit  31 , green image generating unit  33  and blue image generating unit  32  each include an outgoing side polarizing plate, a liquid crystal panel and an incidence side polarizing plate arranged sequentially from the color synthesis prism  30 . 
         [0039]    The red light, green light and blue light that have entered the color synthesizer  3  pass through the red image generating unit  31 , green image generating unit  33  and blue image generating unit  32 , respectively, and enter the color synthesis prism  30 . 
         [0040]    The image light of the three colors guided to the color synthesis prism  30  is synthesized by the color synthesis prism  30 , and the resulting color image light is magnifyingly projected through a projection lens  20  onto a forward screen. 
       Lamp Unit 
       [0041]    As shown in  FIG. 3 , the outer holder  7  containing the lamp unit  4  is located close to the exhaust vent provided in the rear panel  17  of the casing  1 . As shown in  FIG. 5  and  FIG. 6 , the outer holder  7  contains the lamp unit  4  held by an inner holder  5 . The lamp unit  4  has a light emitting tube  42  and a parabolic reflector  41  surrounding the light emitting tube  42 . A discharge emission lamp such as a metal halide lamp or an extra-high pressure mercury lamp, for example, may be used as the lamp unit  4 . 
         [0042]    As shown in  FIG. 9 , the inner holder  5  includes a front wall  50  with a rectangular outline, a first side wall  51 , a second side wall  52  and a third side wall  53  approximately perpendicular to the front wall  50 . As shown in  FIG. 5 , the front wall  50  of the inner holder  5  is located in an outgoing direction of light of the lamp unit  4 . The front wall  50  is provided with a light outgoing hole  49  for passing the light from the lamp unit  4 . 
         [0043]    As shown in  FIG. 7 , the first side wall  51 , second side wall  52  and third side wall  53  of the inner holder  5  surround the side of the reflector  41  of the lamp unit  4 . The third side wall  53  of the inner holder  5  is located between the lamp unit  4  and the exhaust vent  15  of the casing  1 , and opposed to the rear panel  17  provided with the exhaust vent  15  of the casing  1 . 
         [0044]    As shown in  FIG. 9 , the third side wall  53  of the inner holder  5  is formed in the form of a frame with a central opening. A first light blocking member  55  is formed in the central opening. The first light blocking member  55  is provided with a plurality of (five, in the example of  FIG. 9 ) holder air vents  54 . The extending direction (X-direction) of the holder air vents  54  is approximately parallel with the extending direction of the exhaust vent  15  of the casing  1 . Each holder air vent  54  provides an air flow passage between the inside of the inner holder  5  and the exhaust vent  15  of the casing  1 . The opening plane (Y-Z plane) of the holder air vents  54  is parallel to the rear panel  17  provided with the exhaust vent  15  of the casing  1 . 
         [0045]    Each holder air vent  54  is formed in the form of a wide rectangle. The width of the holder air vents  54  extends in the direction (Z-direction) perpendicular to the front wall  50  of the lamp unit  4 . In addition, the width of the holder air vents  54  is defined to have a length across the exhaust vent  15  of the casing  1 . The plurality of holder air vents  54  are adjacently provided at approximately regular intervals in the direction (Y-direction) approximately perpendicular to the width direction (Z-direction) of the holder air vents  54 . 
         [0046]    Further, the first light blocking member  55  is provided with a plurality of (five, in the example of  FIG. 9 ) first light blocking plates  56 . The first light blocking plates  56  have a parallel part  57  approximately parallel with the opening plane (Y-Z plane) of the holder air vents  54  between adjacent holder air vents  54 ,  54 , or between a holder air vent  54  and the first side wall  51  of the inner holder  5 . The parallel part  57  of each first light blocking plate  56  is formed across in the width direction (Z-direction) of the holder air vents- 54 . 
         [0047]    Each first light blocking plate  56  includes a flat rectangular inclined part  58  projecting from the corresponding parallel part  57  inward of the inner holder  5 . The projecting direction of the inclined part S 8  of each first light blocking plate  56  is inclined from the opening plane (Y-Z plane) of the holder air vents  54  with a predetermined angle. The inclined parts  58  have a constant dimension (width dimension) in the direction perpendicular to the projecting direction. 
         [0048]    Each holder air vent  54  is covered with the inclined part  58  of the corresponding first light blocking plate  56  inside the inner holder  5 . The distance between the opening plane (Y-Z plane) of the holder air vents  54  and the inclined part  58  of each first light blocking plate  56  becomes large from one end toward the other end in the direction (Y-direction) perpendicular to the width direction (Z-direction) of the holder air vents  54 . 
         [0049]    A pair of side wall parts  59 ,  59  are provided on both sides in the width direction (Z-direction) of the holder air vents  54 , and perpendicularly project from the outer periphery of each holder air vent  54  inward of the inner holder  5 . Projecting ends of the pair of side wall parts  59 ,  59  are coupled to opposite ends in the width direction of the corresponding first light blocking plate  56 . 
         [0050]    The third side wall  53  of the inner holder  5  is exposed from the outer holder  7 . As shown in  FIG. 3 , a second light blocking member  6  is located between the first light blocking member  55  formed in the third side wall  53  of the inner holder  5  and the rear panel  17  provided with the exhaust vent  15  of the casing  1 . 
         [0051]    As shown in  FIG. 12 , the first light blocking member  55  and the second light blocking member  6  are arranged adjacently to each other in the extending direction (X-direction) of the holder air vents  54  of the first light blocking member  55 , so that the first light blocking member  55  and the second light blocking member  6  provide a light blocking mechanism  9 . 
         [0052]    The second light blocking member  6  is made of a metal plate, and, as shown in  FIG. 10 , held inside a frame  60  having a central opening  63 . The second light blocking member  6  is provided with a plurality of (five, in the example of  FIG. 10 ) intermediate air vents  62 . The extending direction (X-direction) of the intermediate air vents  62  is arranged in parallel with the extending direction (X-direction) of the holder air vents  54 . Each intermediate air vent  62  provides an air flow passage between the corresponding holder air vent  54  and the exhaust vent  15  of the casing  1 . 
         [0053]    Each intermediate air vent  62  is formed in the form of a wide rectangle. The width of the intermediate air vents  62  is defined to have a length across the exhaust vent  15  of the casing  1 . The plurality of intermediate air vents  62  are adjacently provided in the direction (Y-direction) approximately perpendicular to the width direction (Z-direction) of the intermediate air vents  62 . As shown in  FIG. 12 , the juxtaposition direction of the plurality of intermediate air vents  62  is parallel with the juxtaposition direction (Y-direction) of the plurality of holder air vents  54 . The juxtaposition distance of the plurality of intermediate air vents  62  is approximately the same as the juxtaposition distance of the plurality of holder air vents  54 . In the light blocking member  6  shown in  FIG. 10 , an intermediate air vent  62  located at one side in the juxtaposition direction (Y-direction) of the plurality of intermediate air vents  62  is coupled to the central opening  63  of the frame  60 . 
         [0054]    The second light blocking member  6  is provided with a plurality of (five, in the example of  FIG. 10 ) second light blocking plates  64 . The second light blocking plates  64  have a parallel part  65  approximately parallel with the opening plane (Y-Z plane) of the intermediate air vents  62  between adjacent intermediate air vents  62 ,  62 , or between an intermediate air vent  62  and the frame  60  of the light blocking member  6 . The parallel part  65  of each second light blocking plate  64  is formed across in the width direction (Z-direction) of the intermediate air vents  62 . 
         [0055]    As shown in  FIG. 12 , the parallel part  65  of each second light blocking plate  64  is arranged approximately parallel with the parallel part  57  of each first light blocking plate  56 . The parallel parts  65  of the plurality of second light blocking plates  64  are adjacently provided at intervals approximately the same as those of the parallel parts  57  of the plurality of first light blocking plates  56 . 
         [0056]    Each second light blocking plate  64  includes a flat rectangular inclined part  66  projecting from the corresponding parallel part  65  toward the first light blocking member  55 . The inclined part  66  of each second light blocking plate  64  is inclined from the opening plane (Y-Z plane) of the intermediate air vents  62  with a predetermined angle, and in a direction approximately perpendicular to the direction in which the inclined part  58  of each first light blocking plate  56  extends from the corresponding parallel part  57 . 
         [0057]    The inclined parts  66  have a constant dimension (width dimension) in the direction perpendicular to the projecting direction. Each second light blocking plate  64  covers the corresponding intermediate air vent  62 , and also covers the corresponding holder air vent  54 . Opposite ends in the direction perpendicular to the projecting direction of each second light blocking plate  64  are coupled to a pair of side wall parts  67 ,  67  projecting from both sides in the width direction (Z-direction) of each intermediate air vent  62 . 
         [0058]    The parallel part  57  of each first light blocking plate  56  and the parallel part  65  of each second light blocking plate  64  are arranged to provide a phase difference therebetween so as to only partly overlap in the disposition direction (X-direction) of the first light blocking member  55  and the second light blocking member  6 . Projecting ends of inclined parts  66 ,  66  of adjacent second light blocking plates  64 ,  64  are arranged close to parallel parts  57 ,  57  of adjacent first light blocking plates  56 ,  56 . 
         [0059]    In such a light blocking mechanism  9 , each holder air vent  54  is covered with the corresponding first light blocking plate  56  on the side close to the lamp unit  4 , and also covered with the corresponding second light blocking plate  64  on the side close to the second light blocking member  6 . Each holder air vent  54  is located between inclined parts  66 ,  66  of adjacent second light blocking plates  64 ,  64 . 
         [0060]    As shown in  FIG. 3 , an exhaust fan device  8  for sucking out the air in the inner holder  5  for exhaust to the outside from the exhaust vent  15  of the casing  1  is arranged between the light blocking member  6  and the rear panel  17  provided with the exhaust vent  15  of the casing  1 . 
         [0061]    Because the lamp unit  4  generates heat when it emits light, airflow is sent into the inner holder  5  from a cooling fan device (not shown), so that the lamp unit  4  is cooled by the airflow. The air that has cooled the lamp unit  4  is heated, and therefore an exhaust fan  80  of the exhaust fan device  8  as shown in  FIG. 8  is rotated to thereby suck out the air in the inner holder  5  toward the exhaust fan device  8 . 
         [0062]    The plurality of holder air vents  54  and the plurality of intermediate air vents  62  providing air flow passages, as shown in  FIG. 12 , are provided between the inside of the inner holder  5  and the exhaust fan device  8 . Although the holder air vents  54  are covered with the respective first light blocking plates  56 , the air in the inner holder  5  can pass through the holder air vents  54  without being blocked by the first light blocking plates  56 , because the first light blocking plates  56  are inclined relative to the opening plane of the holder air vents  54 , and cover the holder air vents  54  without closing the holder air vents  54 . 
         [0063]    Although the holder air vents  54  are covered also with the respective second light blocking plates  64 , the air that has passed through the holder air vents  54  flows to the intermediate air vents  62  without being blocked by the second light blocking plates  64  because each holder air vent  54  is located between inclined parts  66  of adjacent second light blocking plates  64 ,  64 . 
         [0064]    Further, although the intermediate air vents  62  are covered with the respective second light blocking plates  64 , the air that has passed through the holder air vents  54  can pass through the intermediate air vents  62  without being blocked by the second light blocking plates  64 , because the second light blocking plates  64  are inclined relative to the opening plane of the intermediate air vents  62 , and cover the intermediate air vents  62  without closing the intermediate air vents  62 . 
         [0065]    This secures exhaust paths necessary for exhausting the air in the inner holder  5  outside, and eliminates the necessity to speed up the rotation of the exhaust fan  80  even though the first and second light blocking plates  56 ,  64  are provided. This can suppress noise due to the rotation of the exhaust fan  80 . 
         [0066]    As shown in  FIG. 11 , the second light blocking member  6  of the light blocking mechanism  9  is exposed from the exhaust vent  15  of the casing  1  via the exhaust fan device  8 . As shown in  FIG. 8 , the lamp unit  4  is located inside the second light blocking member  6 , but the second light blocking member  6  will not leak outgoing beams of the lamp unit  4 . 
         [0067]      FIG. 12  shows the light blocking mechanism  9  blocking outgoing beams of the lamp unit  4 . As illustrated, the light blocking mechanism  9  blocks beams (arrows a, b, c in the drawing) that have been emitted from the lamp unit  4  and travel in directions within the X-Y plane, and therefore the outgoing beams of the lamp unit  4  will not leak. The light blocking mechanism  9  also blocks beams traveling in the Z-direction with the pair of side wall parts  59 ,  59  provided on both sides of each holder air vent  54  and pair of side wall parts  67 ,  67  provided on both sides of each intermediate air vent  62 . Therefore, the outgoing beams of the lamp unit  4  will not leak from the light blocking mechanism  9  in any direction. 
         [0068]    The present invention is not limited to the foregoing embodiment in construction but can be modified variously by one skilled in the art without departing from the spirit of the invention as set forth in the appended claims. For example, there may be any number of holder air vents  54  and intermediate air vents  62  and any number of first light blocking plates  56  and second light blocking plates  64 . The first light blocking plates  56  may project toward the second light blocking member  6 , and the second light blocking plates  64  may project toward the exhaust vent  15  of the casing  1 . 
         [0069]    Although the above embodiment utilizes the holder air vents  54  and intermediate air vents  62  as exhaust vents for exhausting the air in the inner holder  5 , the holder air vents  54  and intermediate air vents  62  are usable as intake air vents for taking in outside air. In this case, the vent of the casing  1  used as the exhaust vent  15  of the casing  1  in the above embodiment will be utilized as an intake air vent. The exhaust fan device  8  may be omitted.