Abstract:
A projection apparatus including an optical unit for magnifying and projecting an image by using light of a light source and a reflecting member for reflecting the projected image from the optical unit. This projected image is reflected by the reflecting member onto a rear surface of a screen. The projection apparatus further includes a housing containing the light source and which has a plurality of housing surfaces and an air exhausting member for discharging interior heat of the housing with the air exhausting member including an air passage. First and second aperture sections are provided on different housing surfaces from each other for exhausting air from the housing. These first and second aperture sections communicate with the same air passage but are respectively exhausting air from the same air passage in generally perpendicular air path directions.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an improvement of a projection apparatus utilizing light of a light source contained in a housing and projecting an image. 
     2. Description of the Related Art 
     In a projection apparatus, there is a so-to-speak rear surface projection type projecting an image from a rear surface of a screen. Hereinafter, the rear surface projection type projection apparatus is simply called “a projection apparatus”. The projection apparatus is superior to a TV set utilizing a cathode-ray tube in terms of small depth in comparison with the TV set, and it is capable of realizing a size reduction more than the TV set utilizing the cathode-ray tube, as a whole, even if a display area is formed to be large. 
     FIG. 1 shows a perspective view illustrating an example of a constitution for a related projection apparatus. A projection apparatus  1100  has a screen  1061  projected with an image, and a mirror  1062  for reflecting the image, and includes an optical unit  1104 . This optical unit  1104  has a lamp house section, not illustrated, of a lamp to serve as light source, a fan, and a control section therefor. 
     The optical unit  1104  is provided with liquid crystal sections and a projection lens of portions, for example, for three colors of red, green and blue (RGB). The lamp house section is provided with the light source for irradiating light to the optical unit  1104 . The fan is an apparatus for circulating air inside the duct provided in the interior of the projection apparatus  1100 , and for discharging interior heat to an exterior. A prescribed air outlet is provided on a rear surface of the projection apparatus  1100 , and heat inside the duct is discharged to the exterior from the air outlet by means of the fan. 
     The projection apparatus  1100  forms an image out of light from the light source via the liquid crystal section, under a constitution described above, magnifies the image by means of the projection lens of the optical unit  1104 , reflects the projected image by the mirror, and projects the projected image on the screen. The light source generates heat and the projection apparatus  1100  discharges the interior heat to the exterior from the air outlet by means of the fan. 
     In the related projection apparatus  1100 , since there is only one air outlet, in a case where the projection apparatus is installed, when the projection apparatus is utilized in such a blocked state as that a surface provided with the air contact with a wall or the like, and interior temperature is elevated because the interior heat is not discharged to the exterior. When the projection apparatus is utilized in a state described above, there is such a case that a failure has been caused due to elevation of the interior temperature. 
     It is an object of the present invention to provide a projection apparatus capable of efficiently discharging the interior heat to the exterior, and maintaining the interior temperature to appropriate temperature in order to resolve the problems described above. 
     SUMMARY OF THE INVENTION 
     According to one aspect of the present invention, the object described above can be achieved by means of a projection apparatus wherein in the projection apparatus having an optical unit for magnifying and projecting an image by using light of a light source, a reflecting means for reflecting the projected image from the optical unit, and a screen projected with the projected image from the reflecting means from a rear surface, wherein the projection apparatus further includes a housing containing the light source and having a plurality of surfaces, and an air exhausting means for discharging the interior heat of the housing, wherein at least one of the air outlets is respectively provided on a plurality of surfaces of the housing on surfaces different from each other. 
     According to a constitution of the aspect, an optical unit magnifies and projects an image by using light of a light source. A reflecting means reflects the projected image from the optical unit, and a screen is projected from rear surface the projected image, wherein the projection apparatus discharges the interior heat of the projection apparatus from the other air outlet even if one of the air outlets is blocked by means of a wall or the like. Accordingly, the projection apparatus discharges efficiently the interior heat to the exterior, and capable of appropriately maintaining the interior temperature. 
     According to another aspect of the present invention, at least one of the air outlets is provided on a bottom surface side of the housing to form a passage of heat between an arrangement surface and a bottom surface when the housing is arranged. 
     According to a constitution of the aspect, even up to a side surface or a rear surface is blocked by means of an adjacent wall or the like, interior heat of the projection apparatus is discharged from an air outlet provided on a bottom section side of the housing via a prescribed passage. Accordingly, since air exhaust is appropriately carried out, even if the side surface or the rear surface is covered, the projection apparatus efficiently discharges interior heat to exterior, so that interior temperature can appropriately be maintained. 
     According to another aspect of the present invention, at least one of the air outlets is provided on a rear surface side of the housing 
     According to still another aspect of the present invention, the air outlets include a first air outlet provided on a first surface out of a plurality of surfaces of the housing described above, and a second outlet provided on a second surface except the first surface of the housing described above. 
     According to still another aspect of the present invention, in a case where the first air outlet is blocked, the interior heat of the projection apparatus is discharged from the second air outlet. Accordingly, the projection apparatus discharges the interior heat efficiently to the exterior, thereby enables the interior temperature to be maintained in an appropriate state. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a perspective view illustrating an example of a constitution for a related projection apparatus. 
     FIG. 2 shows a front view illustrating an example of constitution of a projection apparatus as a preferred embodiment of the present invention. 
     FIG. 3 shows a section view illustrating an example of an interior constitution of the projection apparatus in FIG. 2 in a case where it is viewed from the front. 
     FIG. 4 shows a section view illustrating an example of a rough constitution of the projection apparatus in FIG. 2 in a case where it is sectioned on line C-C′ in FIG.  2 . 
     FIG. 5 shows a section view illustrating an example of a rough constitution of the projection apparatus in FIG. 2 in a case where it is sectioned on line A-A′ in FIG.  2 . 
     FIG. 6 shows a section view illustrating an another example of a rough constitution of the projection apparatus in FIG. 2 in a case where it is sectioned on line B-B′ in FIG.  2 . 
     FIG. 7 shows a perspective view illustrating an example of a detailed exploded constitution for a light source section and a case in FIG.  3 . 
     FIG. 8 shows a section view illustrating an example of constitution wherein a light source section and a case in FIG. 7 are contained in a lower section of a housing in FIG.  3 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereinafter, favorable embodiments of the present invention will be described in detail based on the attached drawings. 
     In the mean time, since embodiments described herein after are favorable concrete examples of the present invention, various and technically preferred limitations are imposed on a scope of the invention, however, in the explanation hereinafter, unless there is any specific description of limiting the scope of the invention, the present invention is not intended to be limited to these embodiments. 
     FIG. 2 shows a front view illustrating an example of constitution of a projection apparatus as a preferred embodiment of the present invention. 
     The projection apparatus  100  has such a constitution as vertically separable substantially at its intermediate portion, and is composed of an upper section cabinet  102  and a lower section cabinet  103 . The upper section cabinet  102  and the lower ;section cabinet  103  are formed respectively in an independent state, and the upper section cabinet  102  is constituted to be assembled relative to the lower section cabinet  103 . 
     The upper section cabinet  102  is mounted with a screen  61  in a front surface section  110  of a housing  101  in a shape of rectangular parallelepiped. Further, the housing  101  is formed in a box shape an interior thereof is a cavity, as a whole, and a circumference thereof is closed by means of an upper surface wall, both side surface walls, a rear surface wall and a bottom surface wall. The upper surface wall and both the side surface walls are inclined to a rear surface side of the wall, and the inclined surface of the upper surface wall is provided with the mirror illustrated in FIG. 3 to be parallel to the inclined surface. As illustrated in FIG. 4, in particular, the inclined surface wall is formed of a state having an inclination angle previously calculated taking into account a positional relationship preset between the screen  61  mounted on the front surface section  110  of the housing  101  and reflection of an image by means of a projection lens, which will be described later. 
     The entire equipment components necessitated as the projection apparatus  100  are installed in the lower section cabinet  103  except the screen  61  and the mirror provided in the upper section cabinet  102  described above. In an interior of the lower section cabinet  103 , a projected image equipment including three pieces of liquid crystal section and their drive circuit as a main component section, for example, and the projection lens are provided substantially in the central section, a light source  2  is provided detachably at a position either left or right of the central section of the lower section cabinet  103  (in the present embodiment, it is on a right side). The light source  2  can be inserted into or removed from a lamp insertion port  2   a.    
     The liquid crystal section described above is brought into high picture quality by utilizing three pieces of, for example, small sized and highly precisely formed polysilicon TFT liquid crystal panels which are portions of three colors for red, green and blue RGB and constitutes so-to-speak an optical unit including the projection lens. As the drive circuit described above, the circuit mounted with a plurality of necessary electronic components on a printed circuit board, for example, is employed. 
     The light source  2  described above utilizes, for example, a high intensity discharge lamp with high performance (HID lamp), the whole are made in cartridge types, and are constituted to be easily replaceable from the lamp inserting port  2   a . A front surface of the lower section cabinet  103  including the light source  2  and the lamp insertion port  2   a  is covered by prescribed panel, not illustrated. 
     FIG. 3 shows a section view illustrating an example of an interior constitution of the projection apparatus in FIG. 2 in a case where it is viewed from the front. 
     The lower section cabinet  103  has an electric circuit  51 , an optical unit  104 , and a light source section  200  (light source  2 ). The optical unit  104  is provided substantially at a center lower section of the lower section cabinet  103 . The electric circuit  51  is provided respectively, for example, on the left side and right side of the optical unit  104 . The light source section  200  has the light source  2 , a fan  52  (air exhausting means), and a case  45 . The fan  52  is used for cooling the light source  2  and the like. Heat generated by the light source  2  of the light source section  200  and the like is emitted from air an outlet, which will be described later, to the exterior. 
     FIG. 4 shows a section view illustrating an example of a rough constitution of the projection apparatus in FIG. 2 in a case where it is sectioned on line C-C′. 
     As described above, a mirror  62  (reflecting means) is provided in parallel along the inclined surface of the upper surface wall of the upper section cabinet  102 , a projected image from the optical unit  104  is reflected on a rear surface of a screen  61 . The projection apparatus  100  projects a magnified and projected image on the screen  61  after the projected image from the optical unit  104  fixed to a prescribed base section, not illustrated, is reflected by means of the mirror  62 . With the constitution described above, the magnified and projected image is displayed on the screen  61  on a side of a front surface  110  of the projection apparatus  100 . 
     FIG. 5 shows a section view illustrating an example of a rough constitution of the projection apparatus in FIG. 2 in a case where it is sectioned on line A-A′ in FIG.  2 . 
     Referring to a scope W, the projection apparatus  100  is provided with the light source section  200  as illustrated in FIG.  3 . At a lower section of the light source section  200 , an air exhaust duct  48  is provided for emitting heat of the light source  2  and the like described above, and an air passage  77  is formed by means of the air exhausted duct  48 . An airflow R 3  is generated inside the air passage  77  by means of the fan  52  illustrated in FIG. 3, described above. 
     This projection apparatus  100  includes the housing  101  having a plurality of faces, and a first aperture section  111  (air outlet, a first air outlet) communicating with an air passage  77  (air exhaust means) is provided on either surface of the housing  101 , for example, a rear surface section  107  (a first surface). 
     This projection apparatus  100  is characterized in that a second aperture section  108  (air outlet, a second outlet) other than the first aperture section  111  communicated with the air passage  77  is provided on a surface different from a surface where the first aperture section  111  is provided, for example, on a bottom surface section  106  (a second surface). In the meantime, the second aperture section  108  may well be provided on the surface other than the bottom surface section  106  described above. Further, the second aperture section  108  may well have such a constitution that a plurality of the second aperture sections  108  are provided on the housing  101 , and these aperture sections may have a constitution where they are provided on the respectively different surfaces, or may well have a constitution where they are provided on an identical surface. 
     The second aperture section  108  communicates with the first aperture section  111 , for example, in the air passage  77 . The first aperture section  111  is the section for discharging heat to the rear surface section  107  side of the projection apparatus  110 , however in contrast with that, the second aperture section  108  is the section for discharging heat to the bottom surface section  106  side. The bottom surface section  106  of the projection apparatus  100  has such a constitution as holding a slight clearance for releasing heat, so that heat is never to be confined. 
     In the projection apparatus  100 , when a plurality of air outlets are provided as described above, even if the first aperture section  111  is covered with a wall or the like, for example, in the projection apparatus  100 , it is appropriately discharged from the second aperture section  108 . Further, on the contrary to that, even if the second aperture section  108  is covered by something in the projection apparatus  100 , heat is appropriately discharged from the first aperture section  111 . Accordingly, in the projection apparatus  100 , even if either of the aperture sections is covered, interior heat can efficiently be discharged, so that interior temperature of the housing  101  can be appropriately held by means of the fan  52   
     The projection apparatus  100 , except the constitution described above, may well have a constitution as illustrated hereinafter. 
     FIG. 6 shows a section view illustrating an another example of a rough constitution of the projection apparatus in FIG. 2 in a case where it is sectioned on line B-B′ in FIG.  2 . 
     In projection apparatus  100 , a second aperture section  108   a  (air outlet, the second air outlet) may well have such a constitution as that the air outlet is provided on either of one side of the side surface sections or the air outlets are provided on both sides of the side surface sections. With the constitution described above, the projection apparatus  100  can achieve similar effect to that in the case of the constitution described above. 
     FIG.7 shows a perspective view illustrating an example of a detailed exploded constitution of the light source section  200  and the case  45  in FIG.  3 . 
     FIG. 8 shows a section view illustrating an example of constitution wherein the light source section  200  and the case  45  in FIG. 7 are contained in a lower section of the housing  101  in FIG.  3  and are equivalent to the scope W in FIG.  5 . 
     The light source section  200  and the case  45  constitute a light-source mounting device  300 . The light source section  200  has a light source holder  41  and a light source case  43 . The light source holder  41  has two pieces of pins  41   a  and  41   a , and two pieces of ribs  41   b  and  41   b.    
     The pins  41   a  and  41   a  are protruded toward in an opposite direction along in a direction (in an horizontal direction) to cross at light angle with respect to an optical axis OP of the light source  2 . The ribs  41   b  and  41   b  have a shape of bilateral symmetry around the optical axis OP, the rib  41   b  and  41   b  are formed to be parallel in a Z direction. 
     The case  45  is the case capable of containing the light source section  200  as illustrated in FIG. 6, and has oblong grooves  45   a  and  45   b . These oblong grooves  45   a  and  45   b  are formed to be in parallel to a Z direction which is a vertical direction. The oblong grooves  45   a  and  45   b  are formed respectively in the Z direction on wall surfaces  45   f  and  45   g  of the case  45 . The Z direction is the vertical direction relative to the optical axis OP. 
     The pins  41   a  of the light source holder  41  is respectively fitted in the oblong grooves  45   a . The ribs  41   b  of the light source holder  41  are fitted in the oblong grooves  45   b . This light source holder  41  together with the light source  2  can be positioned by moving in a upper direction along the long grooves  45   a  and  45   b  by means of a member having a cam, for example, not illustrated and by lifting from an entrance position  180  of the light source  2  illustrated in FIG. 8 to a regular position  190  (to a mounting position of the light source relative to the optical unit  104 ). 
     The case  45  is formed to be substantially U in shape, for example, viewed in section, and has an air exhaust duct  48  (air exhaust means). The case  45  and the air exhaust duct  48  are formed of an air exhaust passage for cooling light source holder  41 , a light source case  43 , and a light source  2  of the light source section  200 . 
     The air exhaust duct  48  is integrally formed with the case  45 , and the air exhaust duct  48  has a section of an air passage  77  being substantially rectangular in shape as illustrated in FIG.  7 . In a midway of the air passage  77  of the air exhaust duct  48  are preferably formed of an air throttle portion  79  and two aperture sections  48   a  and  48   a . Specifically, the projection apparatus  100  is formed in a shape after increasing flow speed of air flowing the interior by throttling one section of the air exhaust duct  48  by means of an air throttle portion  79  and then widening the duct, and is constituted so as to open the aperture section  48   a  of an appropriate dimension on a side surface of the widened portion of the duct. Accordingly, the projection apparatus  100  can draw in much more exterior cold air of the air exhaust duct  48  through the aperture section  48   a . With the constitution described above, the projection apparatus  100  is capable of decreasing in exhaust temperature of air cooled the light source  2  and discharged from the air exhaust duct  48 . 
     As illustrated in FIG. 8, in an upper section of the optical unit  104 , the fan  52  is provided for sucking outside air from exterior of the housing  101  through the aperture section  109 . The fan  52  resides in the midway of a guiding duct  149  (air exhaust means) formed of the housing  101  and a partitioning plate  129 . The fan  52  is the fan for intake which supplies air taken in from the aperture section  109  of the upper section on the rear side of the housing  101  to the light source section  200  side. 
     The fan  52 , the light source section  200 , the case  45 , and the air exhaust duct  48  are contained in the lower section cabinet  103  of the housing  101 . The end section of the air exhaust duct  48  is connected to the first aperture section  111  and the second aperture section  108  of the lower section on the rear side of the lower section cabinet  103  as described above. 
     The projection apparatus  100  has the constitution described above, and next a cooling operation of the light source  2  of the light source section  200  will be explained with reference to FIG.  2  through FIG.  8 . 
     Cooling air fed by the fan  52  for cooling, is passed along in a R 1  direction and R 2  direction as illustrated in FIG.  8  through the guiding duct  149  formed in the housing  101  and the partitioning plate  129 , and fed to the light source  2 . A passage is structured in such a manner as that air taken away and warmed by heat generated by the light source  2  is passed through the lower section of the light source holder  41 , goes through the interior of the case  45  along in a R 3  direction and the air exhaust duct  48  and is guided from either of the first aperture section  111  and the second aperture section  108  or both of them and to the exterior. Here, even if the first aperture section  111  is covered by something, air is guided to the exterior of the housing  101  from the second aperture section  108 . 
     According to the embodiment of the present invention, in the projection apparatus  100 , even if the first aperture  111  is covered, interior heat can be discharged from the second aperture  108 . Accordingly, in the projection apparatus  100 , even if the first aperture  111  is covered, interior temperature can appropriately be maintained. As a contrary, further, the projection apparatus  100  can discharge interior heat from the first aperture  111  even if the second aperture is covered. Accordingly, the projection apparatus  100  can appropriately maintain interior temperature even in a case where the second aperture  108  is covered. 
     The present invention will not be limited to the embodiments described above. 
     In respective constitution of the embodiments described above, part of the constitution can be omitted or the part of the constitution can be combined optionally to be different from the manner described above. 
     Further, the embodiments described above is the projection apparatus of three plate piece type having three pieces of liquid crystal light bulb, not limited to that, and single plate type projection apparatus may, of course, have a single piece of liquid crystal light bulb. In the meantime, the housing  101  can have various shapes not only in the shape illustrated in drawings. 
     Further, the housing  101  may have a round shape, as a whole, not limited to a shape constituted by a typical polyhedron as shown in the embodiment described above. In this case, the housing is included in the scope of the present invention if the housing  101  has a curved face confronting to spatially a plurality of directions and is formed of the air outlets corresponding to these plurality of directions. 
     Still further, it is to be understood that the embodiments described above may be applied to a projection apparatus except the rear face projection type arrangement.