JP5197119B2 - Image projection apparatus and image display system - Google Patents

Description

  The present invention relates to an image projection apparatus that projects an image onto a projection surface such as a screen using a lamp.

  A lamp such as an ultra-high pressure mercury lamp is often used as a light source of an image projection apparatus such as a liquid crystal projector.

  In an image projection apparatus using such a lamp, it is necessary to maintain the temperature of the arc tube of the lamp within an appropriate range, and therefore forced cooling of the lamp with air using a cooling fan is performed. The lamp is generally composed of a reflector and an arc tube arranged inside the reflector, and the inside of the reflector (the arc tube) and the outer surface of the reflector (lamp) are each cooled by air.

  Normally, the lamp is arranged near the exhaust port formed in the housing of the image projection apparatus, and the air that has become hot due to cooling of the lamp is quickly evacuated by an exhaust fan provided between the lamp and the exhaust port. It is discharged out of the housing.

  However, if the high-temperature air that has cooled the lamp is exhausted as it is from the exhaust port, hot air is blown to the user located in the vicinity of the exhaust port, causing discomfort. For this reason, it is necessary to lower the temperature of the air that has cooled the lamp as much as possible and exhaust it from the exhaust port.

Patent Document 1 discloses a cooling structure that lowers the temperature of air exhausted outside the housing by mixing air that has cooled the lamp and air that has cooled the power source of the image projection apparatus and the lamp lighting power source. ing.
JP 2002-023261 A

  However, in the cooling structure disclosed in Patent Document 1, since the power source of the apparatus and the power source for lighting the lamp are also heat-generating components, the air whose temperature is considerably increased by cooling them is mixed with the air that has cooled the lamp. Even so, the exhaust temperature cannot be lowered sufficiently.

  It is also important to reduce noise generated from cooling fans and exhaust fans by increasing the cooling efficiency of the lamp.

The present invention provides an image projection apparatus and an image display system that can perform efficient cooling of a lamp and can sufficiently exhaust the air that has cooled the lamp.

An image projection apparatus according to one aspect of the present invention is an image projection apparatus that uses a lamp having a reflector and an arc tube disposed inside the reflector, and includes a cooling fan and air from the cooling fan. An air guide path that leads to the inside of the reflector, an air inlet formed in the housing of the image projection apparatus, a light shielding means that blocks light from the lamp toward the air inlet, and an air outlet formed in the housing And the lamp is housed inside a lamp box disposed inside the housing, and the lamp box faces the air inlet and receives air sucked from the air inlet. An opening for taking in the inside of the box is formed, and the air that has been sucked in from the air inlet and passed through the region facing the outer surface of the reflector, together with the air that has passed through the inside of the reflector, Characterized in that it is configured to be discharged to the outside of the housing through the outlet port.

  The image projection apparatus and an image supply apparatus that supplies image information to the image projection apparatus also constitute another aspect of the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, while being able to perform efficient cooling inside and outside the reflector in a lamp | ramp, the temperature of the air which cooled the lamp | ramp can fully be lowered | hung, and it can exhaust.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows the configuration of a liquid crystal projector (image projection apparatus) that is Embodiment 1 of the present invention.

  In the following description, “lower” means the bottom surface (lower outer case described later) side of the projector, and “upper” means the upper surface (upper outer case described later) side of the projector. This is the same even when the projector is mounted upside down with the projector turned upside down. “Front” means the side where a projection lens barrel, which will be described later, is exposed, and “rear” means the opposite side.

  In this figure, reference numeral 1 denotes a light source lamp (hereinafter simply referred to as a lamp), and a high-pressure mercury discharge lamp is used in this embodiment. However, as the light source lamp 1, a discharge lamp (for example, a halogen lamp, a xenon lamp, or a metal halide lamp) other than the high-pressure mercury discharge lamp may be used.

  2 is a lamp holder for holding the lamp 1, 3 is explosion-proof glass, and 4 is a glass retainer.

  α denotes an illumination optical system that converts the light beam from the lamp 1 into a parallel light beam having a uniform brightness distribution. β is a color separation / synthesis optical system that color-separates the light from the illumination optical system α, guides it to a reflective liquid crystal panel (not shown) for three colors of RGB, and further color-synthesizes the light from the liquid crystal panel. is there.

  Reference numeral 5 denotes a projection lens barrel that projects light (image) from the color separation / synthesis optical system β onto a screen (projected surface) (not shown). A projection optical system is housed in the projection lens barrel 5.

  Reference numeral 6 denotes an optical box that houses the lamp 1, the illumination optical system α, and the color separation / synthesis optical system β and to which the projection lens barrel 5 is fixed. In the optical box 6, an inlet 6 a (see FIGS. 4 to 6) is formed in a lamp box portion 6 b that houses the light source lamp 1.

  Reference numeral 7 denotes an optical box lid that covers the optical box 6 with the illumination optical system α and the color separation / synthesis optical system β accommodated therein.

  Reference numeral 8 denotes a PFC power supply board that creates a DC power supply from the commercial power supply to each board, and 9 denotes a power supply filter. Reference numeral 10 denotes a ballast power supply unit that operates together with the PFC power supply board 8 to drive the lamp 1 to light.

  Reference numeral 11 denotes a control board which controls the liquid crystal panel and controls the lighting of the lamp 1 via an RGB board described later.

  12A and 12B are first and second for cooling optical elements such as a liquid crystal panel and a polarizing plate in the color separation / synthesis optical system β by sucking air from an air inlet 21a of the lower exterior case 21 described later. It is an optical system cooling fan. Reference numeral 13 denotes a first RGB duct that guides the wind from both optical system cooling fans 12A and 12B to the optical elements in the color separation / synthesis optical system β.

  Reference numeral 14 denotes a lamp cooling fan that sends a blowing air to the lamp 1 to cool the lamp 1. A first lamp duct 15 guides the cooling air to the lamp 1 while holding the lamp cooling fan 14. Reference numeral 16 denotes a second lamp duct that holds the lamp cooling fan 14 and forms a duct that is an air guide path together with the first lamp duct 15.

  Reference numeral 17 denotes a power supply cooling fan for cooling the air by sucking air from an air inlet 21b provided in the lower exterior case 21 and allowing air to flow through the PFC power supply board 8 and the ballast power supply unit 10. Reference numeral 18 denotes an exhaust fan, which discharges air from the lamp cooling fan 14 sent to the lamp 1 and cooled it from an exhaust port 24a formed in the second side plate B24 described later.

  The lower exterior case 21 houses the lamp 1, the optical box 6, the PFC power supply board 8, the ballast power supply unit 10, the control board 11, and the like.

  Reference numeral 22 denotes an upper outer case for covering the lower outer case 21 with the optical box 6 and the like stored therein.

  Reference numeral 23 denotes a first side plate, which closes a side opening formed by the outer cases 21 and 22 together with the second side plate 24. The lower exterior case 21 has the above-described intake ports 21a and 21b, and the second side plate 24 has the above-described exhaust port 24a. The lower exterior case 21, the upper exterior case 22, the first side plate 23, and the second side plate 24 constitute a housing of the projector.

  Reference numeral 25 denotes an interface (IF) board on which a connector for capturing various signals is mounted.

  An exhaust box 27 guides the exhaust from the lamp 1 to the exhaust fan 18 so as not to diffuse the exhaust into the housing. The exhaust box 27 holds lamp exhaust louvers 19 and 20 having a light shielding function for preventing light from the lamp 1 from leaking outside the apparatus.

  Reference numeral 28 denotes a lamp lid. The lamp lid 28 is detachably disposed on the bottom surface of the lower exterior case 21 and is fixed by a screw (not shown). Reference numeral 29 denotes a set adjustment leg. The set adjustment leg 29 is fixed to the lower exterior case 21, and the height of the leg part 29a can be adjusted. The tilt angle of the projector can be adjusted by adjusting the height of the leg 29a.

  Reference numeral 30 denotes an RGB intake plate that holds a dust removal filter (not shown) attached outside the intake port 21a of the lower exterior case 21.

  Reference numeral 31 denotes a prism base that holds the color separation / synthesis optical system β. Reference numeral 32 denotes a box side cover having a duct-shaped portion for guiding cooling air from the first and second optical system cooling fans 12A and 12B in order to cool the optical elements and the liquid crystal panel in the color separation / synthesis optical system β. Reference numeral 33 denotes a second RGB duct that forms a duct together with the box side cover 32.

  Reference numeral 34 denotes an RGB substrate, which is connected to three liquid crystal panels arranged in the color separation / synthesis optical system β via a flexible substrate, and drives each liquid crystal panel according to a control signal from the control substrate 11. Reference numeral 35 denotes an RGB substrate cover for preventing electrical noise from entering the RGB substrate 34.

  Next, an optical system constituted by the lamp 1, the illumination optical system α, the color separation / synthesis optical system β, and the projection lens barrel 5 will be described with reference to FIG.

  2A shows a horizontal section of the optical system, and FIG. 2B shows a vertical section.

  In the figure, reference numeral 41 denotes a discharge arc tube (hereinafter simply referred to as an arc tube) that emits white light in a continuous spectrum. Reference numeral 42 denotes a reflector having a concave mirror that condenses light from the arc tube 41 in a predetermined direction. The light source lamp 1 is constituted by the arc tube 41 and the reflector 42.

  Reference numeral 43a denotes a first cylinder array in which a plurality of cylindrical lens cells having refractive power in the horizontal direction shown in FIG. 43b is a second cylinder array having a plurality of cylindrical lens cells corresponding to the individual lens cells of the first cylinder array 43a. 44 is an ultraviolet absorption filter, and 45 is a polarization conversion element that converts non-polarized light into predetermined polarized light.

  Reference numeral 46 denotes a front compressor composed of a cylindrical lens having a refractive power in the vertical direction shown in FIG. Reference numeral 47 denotes a reflection mirror for bending the optical axis from the lamp 1 by approximately 90 degrees (more specifically, 88 degrees).

  43c is a third cylinder array in which a plurality of cylindrical lens cells having refractive power in the vertical direction are arranged. 43d is a fourth cylinder array having a plurality of cylindrical lens arrays corresponding to individual lens cells of the third cylinder array 43c.

  Reference numeral 50 denotes a color filter for returning the color in a specific wavelength region to the lamp 1 in order to adjust the color coordinates to a predetermined value. Reference numeral 48 denotes a condenser lens. Reference numeral 49 denotes a rear compressor composed of a cylindrical lens having a refractive power in the vertical direction. The illumination optical system α is configured as described above.

  58 is a dichroic mirror that reflects light in the wavelength region of blue (B: for example 430 to 495 nm) and red (R: for example 590 to 650 nm) and transmits light in the wavelength region of green (G: for example 505 to 580 nm). is there. 59 is an incident side polarizing plate for G in which a polarizing element is bonded to a transparent substrate, and transmits only P-polarized light. Reference numeral 60 denotes a first polarization beam splitter that transmits P-polarized light and reflects S-polarized light on a polarization separation surface constituted by a multilayer film.

  61R, 61G, and 61B are a reflective liquid crystal panel for red, a reflective liquid crystal panel for green, and a reflective liquid crystal panel for blue as light modulation elements (or image forming elements) that reflect incident light and modulate the image, respectively. is there. 62R, 62G, and 62B are a quarter wavelength plate for red, a quarter wavelength plate for green, and a quarter wavelength plate for blue, respectively.

  A trimming filter 64a returns orange light to the lamp 1 in order to increase the color purity of the R light. Reference numeral 64b denotes an incident-side polarizing plate for RB in which a polarizing element is attached to a transparent substrate and transmits only P-polarized light.

  65 is a color selective phase difference plate that converts the polarization direction of the R light by 90 degrees and does not convert the polarization direction of the B light. Reference numeral 66 denotes a second polarization beam splitter that transmits P-polarized light and reflects S-polarized light on the polarization separation surface.

  Reference numeral 68B denotes a B-use exit side polarizing plate (polarizing element) that rectifies only the S-polarized component of the B light. 68G is a G output-side polarizing plate that transmits only the S-polarized light component of the G light. Reference numeral 69 denotes a dichroic prism that transmits R light and B light and reflects G light.

  The above dichroic mirror 58 to dichroic prism 69 constitute a color separation / synthesis optical system β.

  In this embodiment, the polarization conversion element 45 converts P-polarized light to S-polarized light. The P-polarized light and S-polarized light described here are described with reference to the polarization direction of light in the polarization conversion element 45. On the other hand, the light incident on the dichroic mirror 58 is assumed to be P-polarized light considering the polarization directions in the first and second polarization beam splitters 60 and 66 as a reference. That is, in this embodiment, the light emitted from the polarization conversion element 45 is S-polarized light, but when the same S-polarized light is incident on the dichroic mirror 58, it is defined as P-polarized light.

  Next, the optical action will be described. Light emitted from the arc tube 41 is collected in a predetermined direction by the reflector 42. The reflector 42 has a parabolic concave mirror, and light from the focal position of the paraboloid becomes a light beam parallel to the symmetry axis of the paraboloid. However, since the light source from the arc tube 41 is not an ideal point light source and has a finite size, the condensed light flux includes many light components that are not parallel to the symmetry axis of the paraboloid. ing. These light beams are incident on the first cylinder array 43a. The light beam incident on the first cylinder array 43a is divided into a plurality of light beams corresponding to the number of cylinder lens cells and collected to form a plurality of strip-shaped light beams arranged in the vertical direction. The plurality of split light beams pass through the ultraviolet absorption filter 44 and the second cylinder array 43b to form a plurality of light source images in the vicinity of the polarization conversion element 45.

  The polarization conversion element 45 has a polarization separation surface, a reflection surface, and a half-wave plate. A plurality of light beams are incident on a polarization separation surface corresponding to each column, and are divided into a P-polarized component that transmits the light and an S-polarized component that is reflected there. The reflected S-polarized component is reflected by the reflecting surface and is emitted in the same direction as the P-polarized component. On the other hand, the P-polarized component transmitted through the polarization splitting surface is transmitted through the half-wave plate and converted into the same polarized component as the S-polarized component. Thus, a plurality of light beams having the same polarization direction are emitted.

  The plurality of light beams that have undergone polarization conversion are emitted from the polarization conversion element 45, compressed by the front compressor 46, reflected by the reflection mirror 47, and incident on the third cylinder array 43 c.

  The light beam incident on the third cylinder array 43c is divided into a plurality of light beams corresponding to the number of cylinder lens cells and collected to form a plurality of strip-shaped light beams arranged in the horizontal direction. The plurality of split light beams enter the rear compressor 49 via the fourth cylinder array 43d and the condenser lens 48.

  By the optical action of the front compressor 46, the condenser lens 48, and the rear compressor 49, rectangular images formed by a plurality of light beams overlap each other to form a rectangular uniform brightness illumination area. Reflective liquid crystal panels 61R, 61G, and 61B are disposed in this illumination area.

  The light converted to S-polarized light by the polarization conversion element 45 enters the dichroic mirror 58. Hereinafter, the optical path of the G light transmitted through the dichroic mirror 58 will be described.

  The G light transmitted through the dichroic mirror 58 enters the incident side polarizing plate 59. Even after being decomposed by the dichroic mirror 58, the G light remains P-polarized light (S-polarized light when the polarization conversion element 45 is used as a reference). The G light exits from the incident-side polarizing plate 59, then enters the first polarizing beam splitter 60 as P-polarized light, passes through the polarization separation surface, and reaches the G reflective liquid crystal panel 61G.

  Here, an image supply device 80 such as a personal computer, a DVD player, or a TV tuner is connected to the IF board 25 of the projector. The control board 11 drives the reflective liquid crystal panels 61R, 61G, and 61B based on the image information input from the image supply device 80, and forms an original image for each color on them. Thereby, the light incident on each reflective liquid crystal panel is reflected and modulated (image modulation) according to the original image. The image supply device 80 and the projector constitute an image display system.

  In the G reflective liquid crystal panel 61G, the G light is image-modulated and reflected. The P-polarized component of the image-modulated G light is again transmitted through the polarization separation surface of the first polarization beam splitter 60, returned to the light source side, and removed from the projection light. On the other hand, the S-polarized component of the image-modulated G light is reflected by the polarization separation surface of the first polarization beam splitter 60 and travels toward the dichroic prism 69 as projection light.

  At this time, in a state where all the polarization components are converted to P-polarized light (in a state where black is displayed), a quarter-wave plate 62G provided between the first polarizing beam splitter 60 and the G-use reflective liquid crystal panel 61G. The slow axis is adjusted in a predetermined direction. Thereby, the influence of the disturbance of the polarization state which generate | occur | produces with the 1st polarizing beam splitter 60 and the reflective liquid crystal panel 61G for G can be restrained small.

  The G light emitted from the first polarization beam splitter 60 enters the dichroic prism 69 as S-polarized light, is reflected by the dichroic film surface of the dichroic prism 69, and reaches the projection lens barrel 5.

  On the other hand, the R light and B light reflected by the dichroic mirror 58 enter the trimming filter 64a. R light and B light are still P-polarized light after being decomposed by the dichroic mirror 58. Then, after the orange light component is cut by the trimming filter 64a, the R light and the B light are transmitted through the incident side polarizing plate 64b and are incident on the color selective phase difference plate 65.

  The color-selective phase difference plate 65 has an action of rotating only the polarization direction of the R light by 90 degrees, so that the R light is incident on the second polarization beam splitter 66 as S-polarized light and the B light is incident on P-polarized light.

  The R light incident on the second polarization beam splitter 66 as S-polarized light is reflected by the polarization separation surface of the second polarization beam splitter 66 and reaches the R-use reflective liquid crystal panel 61R. The B light incident on the second polarization beam splitter 66 as P-polarized light is transmitted through the polarization separation surface of the second polarization beam splitter 66 and reaches the B-use reflective liquid crystal panel 61B.

  The R light incident on the R reflective liquid crystal panel 61R is image-modulated and reflected. The S-polarized component of the image-modulated R light is reflected again by the polarization separation surface of the second polarization beam splitter 66, returned to the light source side, and removed from the projection light. On the other hand, the P-polarized component of the image-modulated R light passes through the polarization separation surface of the second polarization beam splitter 66 and travels toward the dichroic prism 69 as projection light.

  The B light incident on the B-use reflective liquid crystal panel 61B is image-modulated and reflected. The P-polarized component of the image-modulated B light is transmitted again through the polarization separation surface of the second polarization beam splitter 66 and returned to the light source side, and is removed from the projection light. On the other hand, the S-polarized component of the image-modulated B light is reflected by the polarization separation surface of the second polarization beam splitter 66 and travels toward the dichroic prism 69 as projection light.

  At this time, by adjusting the slow axes of the quarter-wave plates 62R and 62B provided between the second polarizing beam splitter 66 and the R and B reflective liquid crystal panels 61R and 61B, As in the case, the adjustment in the black display state of each of the R and B lights can be performed.

  The R light and B light that are combined into one light beam and emitted from the second polarization beam splitter 66 are analyzed by the exit-side polarizing plate 68B and enter the dichroic prism 69. Further, the R light is transmitted through the exit-side polarizing plate 68 </ b> B as P-polarized light and enters the dichroic prism 69.

  By being analyzed by the exit-side polarizing plate 68B, the B light is ineffective generated by the B light passing through the second polarizing beam splitter 66, the B reflective liquid crystal panel 61B, and the quarter wavelength plate 62B. The light is cut from the components.

  The R light and B light incident on the dichroic prism 69 pass through the dichroic film surface and are combined with the G light reflected on the dichroic film surface to reach the projection lens barrel 5.

  The combined R, G, B light is enlarged and projected onto a projection surface such as a screen by the projection lens barrel 5.

  Next, the lamp cooling structure in the present embodiment will be described with reference to FIGS. FIG. 3 shows the lamp holder 2 and the lamp 1 in an enlarged manner. FIG. 4 shows the periphery of the lamp box portion 6 b in the optical box 6. 5 and 6 show a cross-sectional structure around the lamp box portion 6b when cut along line AA in FIG.

  In FIG. 3, the lamp holder 2 holds the lamp 1 via a lamp holding member (not shown). An explosion-proof glass 3 is installed on the front surface of the lamp holder 2, and the explosion-proof glass 3 and the lamp holder 2 are held by a glass presser 4.

  The lamp holder 2 and the lamp 1 held by the lamp holder 2 are accommodated inside the lamp box portion 6b described above.

  When the projector is turned on and light is emitted from the arc tube 41 of the lamp 1, the temperature of the lamp 1 rises and the temperature in the lamp box portion 6 b also rises due to heat from the lamp 1.

  An inlet 2 a is formed on the side surface of the lamp holder 2. The inflow port 2a is opposed to the outflow port of a duct (air guide path) formed by the first and second ramp ducts 15 and 16.

  The cooling air (air) sent from the lamp cooling fan 14 that starts rotating in response to the power-on is passed through the ducts 15 and 16 and the inlet 2a as shown by arrows in FIG. It flows into (be led to) the inside of the reflector 42 of the lamp 1 arranged at. Cooling air that has flowed into the inside of the reflector 42 is blown to the spherical light emitting portion 41a of the arc tube 41 and the inner surface of the reflector 42, and cools them.

  The air thus cooled inside the reflector 42 is discharged from the lamp box portion 6b through the outlet port 2c formed in the lamp holder 2 and the outlet port 6c formed in the lamp box portion 6b. The air discharged from the lamp box portion 6b is exhausted from the exhaust port 24a to the outside of the housing through the exhaust box 27 by the rotation of the exhaust fan 18.

  The exhaust fan 18 is disposed between the exhaust box 27 and the exhaust port 24a.

  In addition, an air inlet 21 c is formed in the rear wall surface of the lower exterior case 21. Further, an intake port (opening) 6a is formed at a position facing the intake port 21c in the lamp box portion 6b. The intake port 21c and the intake port 6a are provided with light shielding portions (light shielding means) 210c and 600a, respectively. These light blocking portions 210c and 600a block the light from the lamp 1 toward the intake ports 6a and 21c so as not to leak out of the housing, as indicated by arrows in FIG.

  On the other hand, the light directed from the lamp 1 toward the exhaust box 27 is also blocked by the lamp exhaust louvers 19 and 20, and does not leak out of the casing from the exhaust port 24a.

  When the exhaust fan 18 starts rotating in response to power-on, as shown by an arrow in FIG. 5, the air outside the housing (outside air) is sucked into the housing through the air inlet 21 c by the suction force of the exhaust fan 18. . The sucked outside air is further taken into a region facing the outer surface of the reflector 42 (lamp 1) in the lamp box portion 6b through the air inlet 6a, and on the outer surface of the reflector 42 and outside the reflector 42 in the arc tube 41. The protruding electrode part 41b and its periphery are cooled.

  And the air which cooled the outer surface of the reflector 42, the electrode part 41b of the arc_tube | light_emitting_tube 41, etc. is exhausted in the exhaust box 27 through the outflow port 6c formed in the lamp box part 6b, and also exhausts through the exhaust box 27. The air is exhausted from the opening 24a to the outside of the housing.

  The high-temperature air that has cooled the inside of the reflector 42 (the light emitting portion 41a) is taken from outside the casing and cools the outer surface of the reflector 42, the electrode portion 41b, and the like. In the exhaust box 27. As a result, the temperature of the mixed air is sufficiently lower than the temperature of the air that has cooled the inside of the reflector 42. Thereafter, the mixed air is exhausted from the exhaust port 24a to the outside of the housing.

  Thus, the cooling efficiency of the lamp 1 is improved by forming the inlets 21c and 6a for taking in the outside air in the region facing the outer surface of the reflector 42 (lamp 1) in the casing and the lamp box portion 6b. . As a result, the rotational speeds of the exhaust fan 18 and the lamp cooling fan 14 can be reduced, and the noise of the projector can be reduced. Furthermore, the air that has been heated to a high temperature by cooling the inside of the reflector 42 is mixed with the relatively low temperature air that has cooled the outer surface of the reflector 42, the electrode portion 41b, and the like, and is exhausted from the exhaust port 24a. The exhaust temperature from 24a can be lowered sufficiently.

  Further, since the light inlets 21c and 6a are provided with the light shielding portions 210c and 600a that block the light from the lamp 1, it is possible to make it difficult for the light from the lamp 1 to leak out of the housing.

  7 to 9 show a lamp cooling structure in a projector that is Embodiment 2 of the present invention. FIG. 7 shows a cross section when the periphery of the lamp box portion 6b is viewed from the rear of the lamp 1 (on the electrode portion 41b side). 8 and 9 show a cross-sectional structure around the lamp box portion 6b, as in FIGS.

  The basic configuration of the projector according to the present embodiment is the same as that shown in FIGS. 1 and 2 in the first embodiment, and the same reference numerals as those in the first embodiment are used for the components common to the first embodiment. Attached.

  A heat radiating plate (heat radiating member) 70 is disposed between the optical box 6 (lamp box portion 6b) and the lamp 1 (the outer surface of the reflector 42). The heat dissipation plate 70 has a shape that covers one surface (upper surface) between the optical box 6 and the lamp 1.

  A part of the heat radiating plate 70 is formed with a light shielding portion (light shielding means) 70a disposed in the air inlet 6a of the lamp box portion 6b.

  Further, similarly to the first embodiment, the light shielding portion 210 c is also formed in the air inlet 21 c of the lower exterior case 21.

  The flow of air for cooling the lamp 1 is the same as that of the first embodiment as shown in FIG.

  On the other hand, as shown in FIG. 9, the light from the lamp 1 toward the intake ports 6a and 21c is blocked by the light shielding portions 70a and 210c, and does not leak out of the casing. Light from the lamp 1 toward the exhaust box 27 is blocked by the lamp exhaust louvers 19 and 20 as in the first embodiment.

  In the present embodiment, the heat radiating plate 70 is formed of an aluminum alloy having high thermal conductivity. Further, the surface of the heat radiating plate 70 is subjected to black alumite treatment (antireflection treatment) to suppress reflection of light from the lamp 1.

  In this embodiment, since the heat radiating plate 70 that radiates the heat from the lamp 1 is provided, the cooling efficiency with respect to the radiant heat from the lamp 1 can be further improved.

  Further, since the light shielding part 70a is provided in a part of the heat radiating plate 70, it is not necessary to form a complicated light shielding shape in the optical box 6 (lamp box part 6b). For this reason, the mold structure for molding the optical box 6 which is a molded part can be simplified.

  Further, the anti-reflection treatment is applied to the light shielding portion 70a, so that light directed from the lamp 1 toward the intake port 6a is reflected by the light shielding portion 70a and then further reflected by members in the lamp box portion 6b such as the reflector 42. Thus, it is possible to prevent leakage from the gap of the light shielding portion 70a to the outside of the housing.

  FIG. 10 shows a lamp cooling structure in a projector that is Embodiment 3 of the present invention. FIG. 10 shows a cross-sectional structure around the lamp box portion 6b, as in FIGS. The basic configuration of the projector according to the present embodiment is the same as that shown in FIGS. 1 and 2 in the first embodiment, and the same reference numerals as those in the first embodiment are used for the components common to the first embodiment. Attached.

  However, in this embodiment, the exhaust fan 18 disposed between the exhaust box 27 and the exhaust port 24a in the first and second embodiments is connected to the intake port 21c of the lower outer case 21 and the lamp box portion 6b. It arrange | positions between the inlet ports 6a.

  In the present embodiment, a light shielding portion (light shielding member) 210 c is provided in the air inlet 21 c of the lower exterior case 21.

  The cooling air sent from the lamp cooling fan 14 passes through the ducts 15 and 16 and the inlet 2a of the lamp holder 2 as shown by arrows in FIG. 10, and the reflector 42 of the lamp 1 arranged in the lamp box portion 6b. Flows inside. Cooling air that has flowed into the reflector 42 is blown to the light emitting portion 41a of the arc tube 41 and the inner surface of the reflector 42 to cool them.

  The air thus cooled inside the reflector 42 is discharged from the lamp box portion 6b through the outlet 2c of the lamp holder 2 and the outlet 6c of the lamp box portion 6b. The air discharged from the lamp box portion 6b is exhausted from the exhaust port 27a to the outside of the housing through the inside of the exhaust box 27 as the ventilation from the lamp cooling fan 14 continues.

  When the exhaust fan 18 starts rotating, as indicated by an arrow in FIG. 10, the air outside the casing (outside air) is sucked into the casing through the intake port 21 c by the suction of the exhaust fan 18. The sucked outside air is further blown out from the exhaust fan 18 and taken into a region facing the outer surface of the reflector 42 (lamp 1) in the lamp box portion 6b through the intake port 6a of the lamp box portion 6b. And the outer surface of the reflector 42, the electrode part 41b of the arc_tube | light_emitting_tube 41, and its periphery are cooled.

  The air that has cooled the outer surface of the reflector 42, the electrode portion 41b of the arc tube 41, and the like is exhausted into the exhaust box 27 through the outlet 6c of the lamp box portion 6b as the air blown from the exhaust fan 18 continues. Further, the air is exhausted from the exhaust port 24 a to the outside of the housing through the exhaust box 27.

  Also in this embodiment, the high-temperature air that has cooled the inside of the reflector 42 is taken in from the outside of the housing and cools the outer surface of the reflector 42, the electrode portion 41b, and the like. In the exhaust box 27. As a result, the temperature of the air exhausted from the exhaust port 24a to the outside of the housing is sufficiently lower than the temperature of the air that has cooled the inside of the reflector 42.

  According to this embodiment, since the outside air having a low temperature flows into the exhaust fan 18, the temperature of the electric element mounted on the exhaust fan 18 can be kept low, and thus the life of the exhaust fan 18 can be extended. Is possible.

  Each embodiment described above is only a representative example, and various modifications and changes can be made to each embodiment in carrying out the present invention.

1 is an exploded perspective view of a projector that is Embodiment 1 of the present invention. FIG. 3 is a diagram illustrating an optical configuration of the projector according to the first embodiment. FIG. 3 is a perspective view illustrating a lamp and a lamp holder in the projector according to the first embodiment. FIG. 3 is a perspective view illustrating a configuration around a lamp in the projector according to the first embodiment. FIG. 3 is a cross-sectional view showing the configuration around the lamp and the air flow in the projector according to the first embodiment. FIG. 3 is a cross-sectional view illustrating a configuration around a lamp and a state in which light from the lamp is shielded in the projector according to the first embodiment. Sectional drawing when the lamp box part in the projector which is Example 2 of this invention is seen from back. Sectional drawing which shows the structure of the lamp periphery in the projector of Example 2, and the flow of air. Sectional drawing which shows a mode that the structure around a lamp | ramp and the light from a lamp | ramp in the projector of Example 2 are shielded. Sectional drawing which shows the structure of the lamp periphery in the projector which is Example 3 of this invention, and the flow of air.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light source lamp 2 Lamp holder 3 Explosion-proof glass 4 Glass holder 5 Projection lens barrel 6 Optical box 6a Inlet 6b Lamp box part 600a Light shielding part 14 Lamp cooling fan 15, 16 Lamp duct 18 Exhaust fan 19, 20 Lamp exhaust louver 21 Lower part Outer case 21c Intake port 210c Light-shielding portion 24a Exhaust port 27 Exhaust box 41 Light emitting tube 42 Reflector 70 Heat sink 70a Light-shielding portion

Claims (4)

An image projection apparatus using a lamp having a reflector and an arc tube arranged inside the reflector,
A cooling fan,
An air guide path for guiding air from the cooling fan to the inside of the reflector;
An air inlet formed in the housing of the image projection apparatus;
Light blocking means for blocking light from the lamp toward the air inlet;
An exhaust port formed in the housing,
The lamp is housed inside a lamp box disposed inside the housing;
The lamp box is opposed to the air inlet and has an opening for taking in air sucked from the air inlet into the lamp box.
Air that has been sucked in from the intake port and passed through a region facing the outer surface of the reflector is configured to be discharged to the outside of the casing through the exhaust port together with air that has passed through the inside of the reflector. An image projection apparatus characterized by that. An exhaust fan for exhausting air from the exhaust port;
The image projection apparatus according to claim 1 , wherein air is sucked from the intake port by rotation of the exhaust fan. The light shielding means, the image projection apparatus according to claim 1 or 2, characterized in that provided in the heat radiating member to radiate heat from the lamp. An image projection apparatus according to any one of claims 1 to 3 ,
An image display system comprising: an image supply device that supplies image information to the image projection device.