Abstract: The present invention is a projection type projector apparatus which is provided with a light source portion, a light bulb and a cooler for cooling at least the light source portion, with a silencer which takes exhaust air from the cooler once to damp exhaust sound, and a mounting portion for attachably/detachably mounting the silencer to a projection type projector.

Abstract: A heat-dissipating structure for switching an air direction is provided. The heat-dissipating structure for switching an air direction is used for dissipating the heat generated from a bulb according to one of an upright state and an inverse state of an apparatus provided with the heat-dissipating structure and having a body placing thereon the bulb, including: a wind-supply device and an air direction switching device. The wind-supply device is mounted in the body for supplying a wind flow to a first side of the bulb for dissipating heat along a first wind direction while the apparatus is at the upright state. The air direction switching device is mounted in the body and includes a guiding region for guiding the wind flow to a second opposite side of the bulb along a second wind direction while the apparatus is at the inverse state.

Abstract: The invention provides a projector capable of reducing costs and promoting miniaturization while also being dust-proof. A second sirocco fan with an air-inlet opposing a projection lens is used, and an air-inlet of an outer case is formed on a side face thereof. Thereby, it is difficult for dust to be sucked therein compared with an air-inlet formed on the bottom or top face of the outer case, enabling the projector to be dust-proof without any filter. Since the filter is not required, the number of parts is reduced, thereby reducing costs. Furthermore, the second sirocco fan is placed by utilizing a space under the projection lens, which is liable to be a dead space, enabling the arrangement space to be efficiently used thereby promoting miniaturization of a projector.

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.

Abstract: A cooling device of liquid crystal projector is utilized to cool a liquid crystal panel and polarizer of an optical system in a liquid crystal projector; when the optical system of the present invention is heated by a light projection, coolant will carry the heat of the liquid crystal panel and polarizer of the optical system away, and a flow guiding device is used to lead the coolant to flow so as to cool the high temperature coolant by means of a heat dissipating device, then the heat is dissipated to outside environment thereby. After the temperature of the coolant is lowered, it is led to flow through the liquid crystal panel and polarizer again by means of the flow-guiding device, so as to repeat a cooling cycle.

Abstract: A projector includes a first housing, a second housing, and a sound insulating member. The first housing is provided with first heat-generating elements used for generating an image, first fans producing cooling airflows towards each one of the first heat-generating elements, and vents via which the cooling airflows heated by the first heat-generating elements are discharged. The second housing encloses the first housing, and has second fans discharging the cooling airflows outside the projector. The sound insulating member is provided on a path between the vents and the second fans so as to insulate sound produced by the first fans. The projector may be provided with a dust-proof member for the projecting lens.

Abstract: A projector has a housing, a light source positioned within the housing to generate light, a fan positioned beside the light source to dissipate heat generated by the light source, and an air vent positioned beside the fan to guide heat out of the housing. The air vent reduces turbulence, and thus noise, by the addition of at least one guiding rib. The guiding rib causes heat to flow fluently through the air vent and out of the housing.

Abstract: A lamp house prevents danger when a lamp bulb, acting as a light source in a housing, breaks. The lamp house includes, at inlet and outlet vents for cooling the lamp bulb, movable plates which are movable only toward the inside of the housing of the lamp house. Springs for closing the movable plates are provided and a sensor for detecting opening and closing states of one of the movable plates is disposed on the side of the inlet vent.

Abstract: To provide a projector in which the quality of projected images does not deteriorate when the size of the projector is reduced. A light shielding member for shielding leakage light from gaps between each liquid crystal panel, and a crossed dichroic prism toward a projection lens side is provided. The leakage light from the gaps between each liquid crystal panel and the crossed dichroic prism can be shielded, and only the luminous flux emitted by the crossed dichroic prism can be applied to the projection lens, whereby the quality of projected images does not deteriorate when the device is reduced in size.

Abstract: The projection type display apparatus has liquid crystal panels with polarizers, a light source, a power supply, and a ballast. A cooling device is arranged in the apparatus such that a first set of cooling fans blow cooling air to cool the liquid crystal panels and the polarizers, and a second set of cooling fans suck the cooling air passing through the liquid crystal panels and the polarizers and blow the cooling air to independently cool the light source, the power supply, and the ballast. Therefore, a projection type display apparatus with little light leakage and low noise can be realized. The invention also provides a cooling unit, for the light source, which includes a movable lamp house and a duct with a cooling fan.

Abstract: A projection display device includes an optical unit, a cooling fan for cooling the circumference of light valves of the optical unit, and an exterior cabinet accommodating the optical unit and the cooling fan. The cooling fan is in the form of a sirocco fan. Cooling air of the cooling fan is brought to the circumference of the light valves through a duct, and is distributed by air-quantity controlling means arranged in the duct for effective cooling thereof.

Abstract: A cooling device of liquid crystal projector is utilized to cool a liquid crystal panel and polarizer of an optical system in a liquid crystal projector; when the optical system of the present invention is heated by a light projection, coolant will carry the heat of the liquid crystal panel and polarizer of the optical system away, and a flow guiding device is used to lead the coolant to flow so as to cool the high temperature coolant by means of a heat dissipating device, then the heat is dissipated to outside environment thereby. After the temperature of the coolant is lowered, it is led to flow through the liquid crystal panel and polarizer again by means of the flow-guiding device, so as to repeat a cooling cycle.

Abstract: A projector is provided which is able to facilitate a reduction in size. The projector includes of a lamp information carrier circuit board and a lamp information detection circuit board, and a fuse for determining use and nonuse of a light source lamp. The lamp information carrier circuit board is stacked so as not to overlap the lamp information detection circuit board. For this reason, the lamp information carrier circuit board and the lamp information detection circuit board are stacked close to each other, and the space between the lamp information carrier circuit board and the lamp information detection circuit board can be narrowed.

Abstract: In a display unit wherein an optical block is disposed inside of a housing having a screen at its front, and an image light from the optical block is projected on the screen, a display unit in which the housing is made a closed structure and a path is provided for circulating air between the housing and the optical block so that dust is prevented from entering inside of an apparatus and attaching to optical parts, and at the same time, heat generated in the apparatus can be sufficiently cooled.

Abstract: A projecter having a lamp, a lamp box containing the lamp, an outlet fan for discharging air from the lamp box, an optical system member which receives a light beam from the lamp and outputs an image light, an optical system box containing the optical system member, and an inlet fan for blowing outside air into the optical system box. The projector also has a first ventilating duct that directs the outside air blown in by the inlet fan into the lamp box.

Abstract: A projection display includes a projection lens and first and second light modulators on three sides of a color recombination unit. First and second blower units are respectively disposed on two sides of the projection lens for cooling the light modulators.

Abstract: A projection display includes a projection lens and first and second light modulators on three sides of a color recombination unit. First and second blower units are respectively disposed on two sides of the projection lens for cooling the light modulators.

Abstract: A power supply unit is formed so as to be divided into first and second power supply blocks, which are disposed on both sides of a projecting lens. This allows the power supply blocks to be efficiently disposed in a projection display device, so that dead space is not easily formed in the projection display device, making it possible to reduce the size of the projection display device. First and second power supply block cooling paths are formed at first and second power supply blocks which are liable to generate heat, respectively. A light modulating system cooling path is formed at a light modulating system disposed at substantially the center of the projection display device. Therefore, even when these component parts are closely disposed in the projection display device of a compact size, proper cooling operations can be carried out, making it possible to cool the entire projection display device more efficiently.

Abstract: A display apparatus of the projection type is improved in that, when a lamp valve breaks or is to be replaced, glass fragments and so forth thereof are prevented from being scattered into the inside of an outer housing of a projector apparatus through a cooling air intake port in a portion of the outer casing below the lamp valve and a comparatively small number of cooling fans are used to reduce the size and the weight of the overall display apparatus while optical modulation elements, a light source element and so forth can be forcibly cooled in a high efficiency. Cooling air blasted from an air blasting fan is blasted through an air blasting duct to three spatial optical modulation elements, a PS conversion element and a discharge lamp to forcibly air-cool the elements. A lamp box in which the light source is accommodated and which is removably mounted in an outer housing has a cooling air intake port through which cooling air is taken in to the light source.

Abstract: A display device, such as a reflecting type liquid crystal projector, in which dust is prevented from becoming attached to a reflecting type light valve, such as a liquid crystal panel, and an improvement in cooling effect are attained. The device has a structure having a partition wall for forming an enclosed space including at least an incidence/emission optical system of the reflecting type light valve. The reflecting type light valve is provided in the partition wall such that a light incidence/emission surface of the light valve faces into the side of the enclosed space. A part opposite to the light incidence/emission surface of the reflecting type light valve faces outside the enclosed space. In a structure where a cooling arrangement or a thermal conductive partition wall is connected to the part opposite to the light incidence emission surface, the cooling effect is further improved.

Abstract: A projector is provided that may include an enclosing structure for enclosing an optical path from an electro-optical apparatus to a projection lens, and an air circulation path connected to the enclosing structure and disposed in a flow path for cooling air. Thus, air inside the enclosing structure can be efficiently cooled while preventing the entry of dust or oil mist.

Abstract: A display optical unit and apparatus in which the optical axis of a projection lens is shifted from the optical axis of an illumination unit and light splitter. The projection lens is attachable and detachable in a direction in which the optical axes are shifted from each other. A light valve or a polarizer is cooled by cooling winds blown by a cooling device to the light valve or polarizer through a plurality of wind supply openings are arranged in directions different from one another and within the range of 45 degrees to 315 degrees so as to enable cooling of the display optical unit.

Abstract: In order to provide a projection apparatus capable of discharging the interior heat to an exterior efficiently even when a first air outlet is covered, and capable of maintaining the interior temperature at appropriate temperature, this device is a projection apparatus having an optical unit for magnifying and projecting an image through the use of light of a light source, a reflecting means for reflecting the projected image from the optical unit described above, and a screen on which the projected image from the reflecting means described above is projected from a rear surface, including a housing containing the light source described above and having a plurality of surfaces and further including air exhausting means for discharging interior heat of the housing described above, and is provided respectively with at least one of air outlets on surfaces different from each other out of a plurality of the surfaces of the housing described above.

Abstract: A liquid crystal projector comprises an illuminating optical system including a light source, a color separating optical system for separating illuminating light rays emitted by the illuminating optical system into light rays of three colors, a projection lens unit comprising a projection lens, a cross dichroic prism disposed near a light receiving end of the projection lens, and a plurality of liquid crystal panels arranged around the cross dichroic prism, and a light source power supply for supplying power to the light source. The projection lens unit, the color separating optical system, the illuminating optical system and the light source power supply are arranged in that order. The liquid crystal projector has an outside size in a horizontal plane of 263 mm by 318 mm or below. The liquid crystal panels have a display screen size of 0.9 in. A cooling fan for cooling the plurality of liquid crystal panels is disposed beside the projection lens.

Abstract: In order to prevent dust from sticking to the LCD panel, to prevent the LCD panel from being heated and to suitably adjust the position of the LCD panel, a duct is provided between cooling means for a light source and cooling means for a LCD panel to send cooling air from the LCD panel side to the light source side. Therefore, a light incidence/reflection plane of the LCD panel is disposed in an almost hermetically closed space and an optical path from an integrator lens to the LCD panel is formed in the almost hermetically closed space.

Abstract: A cooling system for a video projector having a high degree of cooling efficiency and preventing an operator from being exposed to hot exhaust air. The system having a case; an intake formed on the case; an outlet formed on the case; a radial fan having an intake side and an exhaust side communicated with the outlet, for blowing air in a direction orthogonal to a rotary shaft thereof; and a cooling duct having an opening opened to a component to be cooled therearound located in the case, and another opening communicated with the intake side of the radial fan. The radial fan induces a negative pressure in the case so as to take a cooling air from outside into inside of the case and to lead the cooling air so as to pass around the component to be cooled before it is directly led into the radial fan through the cooling duct in order to discharge the cooling air outside of the case.

Abstract: A liquid crystal projector, having a configuration in which an exhaust fan is arranged adjacently to a projection lens at an angle to the optical axis of the projection lens, a configuration including a plurality of tilted wind-directing plates, a configuration in which the arrangement of a first reflection mirror, a first lens array, a light source and the exhaust fan is substantially parallel and adjacent to the arrangement of the projection lens, a dichroic prism and a second dichroic mirror, and/or a configuration in which the lens array has the incident surface thereof made of a concave lens.

Abstract: In order to prevent dust from sticking to the LCD panel, to prevent the LCD panel from being heated and to suitably adjust the position of the LCD panel, a duct is provided between cooling means for a light source and cooling means for a LCD panel to send cooling air from the LCD panel side to the light source side. Therefore, a light incidence/reflection plane of the LCD panel is disposed in an almost hermetically closed space and an optical path from an integrator lens to the LCD panel is formed in the almost hermetically closed space.

Abstract: A projection display device is provided that enables well-balanced cooling of a light modulator. A projection display device includes a head body having a surface for mounting a light modulator such as a liquid crystal light valve or the like thereon, and an air inlet for cooling the light modulator provided on the surface, the air inlet is formed to be enlarged on a side opposite to the spiral direction of cooling air sucked by an intake fan arranged below the air inlet and blown out. Therefore, the cooling air sucked by the intake fan is blown from an enlarged portion to cool the light modulator with a good balance.

Abstract: A picture display apparatus and a cooling apparatus used for an optical apparatus for efficiently cooling sections to be cooled through the effective use of air currents supplied from a cooling fan, where in external wall and an internal wall of an air guide section guide rotating air currents generated by the cooling fan to intakes without reducing the air velocity by regulating and directing the air currents in accordance with the shape of the cooling fan and the direction of rotation of the fan. The air currents passing through the air guide section are taken through the intakes into an optical unit and sent to the sections to be cooled including a light valve and a polarizing plate for each color. The sections are thus cooled by the air currents.

Abstract: A liquid crystal projector, having a configuration in which an exhaust fan is arranged adjacently to a projection lens at an angle to the optical axis of the projection lens, a configuration including a plurality of tilted wind-directing plates, a configuration in which the arrangement of a first reflection mirror, a first lens array, a light source and the exhaust fan is substantially parallel and adjacent to the arrangement of the projection lens, a dichroic prism and a second dichroic mirror, and/or a configuration in which the lens array has the incident surface thereof made of a concave lens.

Abstract: An air-cooling apparatus for a projection television is disclosed. The projection television includes a front casing forming an external appearance of a body of the projection television and having a screen installed therein. A rear casing is coupled to the front casing and has a reflection mirror installed therein. A base is integrally formed at a lower portion of the front casing and has an opening and defines a space below the opening. A blowing duct is installed above the opening in the base, and an image projector is installed above the blowing duct and has heat emitting elements including a beam source, dichroic mirrors, a liquid crystal panel and a projection lens therein. A distributing member is disposed within the space and cooperates with the blowing duct so as to distribute air blown by the blowing duct to the heat emitting elements.

Abstract: A projection type picture display apparatus, includes: an illumination optical system; a decomposition optical system; a plurality of liquid crystal display devices; a light synthesizing optical system; an enclosing case for accommodating the illumination optical system and the decomposition optical system; an optical chassis for fixedly mounting various optical elements including the liquid crystal display devices. A first space is formed under both the enclosing case and the optical chassis. A first opening is formed on a side wall of the enclosing case. At least one second opening is formed on the bottom of the enclosing case. At least a third opening is formed on the optical chassis in a position corresponding to at least one of the liquid crystal display devices. A cooling fan is provided in a position adjacent to the above first opening.

Abstract: A front liquid crystal display projector includes a housing having an exhaust port and a projection opening, an optical block, installed in the housing, having a light source, a reflection mirror, a light separator, an image display unit using liquid crystal, an image combining unit, a projection lens, and an exhaust fan installed between the light source and the exhaust port. The reflection mirror changes the direction of the light from the light source, and the projection lens and the light source are disposed parallel to each other. The exhaust port and the projection opening are provided at a first side of the housing. An image formed by the optical block is projected from the first side and from the projection opening, and air in the housing is discharged from the exhaust port and also from the first side. In addition, the exhaust port prevents stray light from the light source, which exits the exhaust port, from overlapping the image projected from the projection opening.

Abstract: A projection display device capable of improving cooling efficiency of the power unit includes a light source lamp unit, a projection lens unit, an exhaust fan provided near the light source lamp unit for ventilating an outer case, and a ventilating path provided inside the power unit. A suction fan is provided at the inlet of the ventilating path which is connected to the cooling air intake port through a duct cover to directly conduct fresh air into the ventilating path. Because the interior of the power unit is cooled by fresh air which is cooler than the air inside the outer case, cooling efficiency is enhanced.

Abstract: A light source such as a metal halide lamp is effectively cooled in an optical apparatus such as a liquid crystal projector. In an optical apparatus which includes a concave mirror 11, a light emitting section 12 arranged in a concave portion of the concave mirror along the optical axis and a cooling structure for cooling a periphery of the light emitting section, the cooling structure is provided with a means for generating an air flow 4, the direction of which is approximately perpendicular to the optical axis of the concave mirror 11, and a means for generating an air flow 5 circulating into the concave portion of the concave mirror 11.

Abstract: A rear projection type image display apparatus having an arrangement that a projection distance of a projection lens thereof is shortened and a density of mounting of parts relating to an optical system and an electric system is made higher. Furthermore, a width of a rear portion of a housing of the rear projection type image display apparatus is reduced rearwards at any position from the upper portion to the lower portion thereof, and the lower portion of a back cover is depressed inwards. Thus, a space required to install the rear projection type image display apparatus can be reduced, the rear surface of the apparatus can be disposed on a wall without any gap when the apparatus is installed along the wall, and the overall body of the apparatus can be received deep into a corner of walls when the apparatus is installed at the corner.

Abstract: A thermal management system is for utilization in a compact display device. A duct is provided within the lamp housing of the display device and a high-wattage light source is mounted within the duct. Multiple cooling fins are mounted to at least one inner surface of the duct and extend into the duct. A thermal radiation absorbent coating, such as black anodization, covers the interior of the duct and the cooling fins and provides for an increased surface absorption of thermal radiation. A port within the duct, which is transparent to visible light, is utilized to direct visible light through a display assembly. An infrared filter, which is reflective or absorptive of infrared radiation, such as a so-called "hot mirror" is utilized to maintain thermal radiation within the duct and a fan is then utilized to pass cooling fluid through the duct, passing the cooling fluid over the cooling fins and removing thermal energy from the display device in a highly efficient manner.

Abstract: An overhead projector includes a housing including a stage which is formed in its top wall and on which a transparency bearing an image to be projected is placed and an air outlet formed in one of its two side walls, an exhaust fan incorporated in the housing for exhausting air in the housing through the air outlet of the housing, a projection light source such as a high illuminance halogen lamp disposed in the housing for illuminating the transparency on the stage from inside the housing, a projection head mounted for projecting a magnified image from the transparency on a screen and including a focusing lens and a reflecting mirror, a column mounted on the housing to hold the projection head over the stage, a Fresnel lens disposed inside the stage to converge light from the light source on the focusing lens of the projection head, a cooling fan, and air guides for guiding air delivered from the cooling fan so that the air flows along a surface of the stage.

Abstract: A projector for separating white light into three primary colors, forming images with liquid crystal light valves, mixing these images, and projecting an enlarged picture of the mixed images with a projection lens. The projector includes an optical unit having a light source, a plurality of dichroic mirrors for separating the white light into blue, green, and red beams, respective liquid crystal light valves forming images of the blue, green, and red colors. The optical unit has a chassis with a rigid center portion at which one of the liquid crystal light valves is mounted, the other two light valves being mounted symmetrically with respect thereto. An adjustment mechanism is provided for matching pixels of the second and third color valves with those of the first color valve. The red color liquid crystal light valve is disposed midway between the blue and green color liquid crystal light valves and a cooling fan is disposed below the red color liquid crystal light valve.

Abstract: A projection display (10) for an electronic data processing device (14) for use in conjunction with an overhead projector (12) is provided. The projection display (10) includes a display with a light transmitting screen (30), and the screen (30) is framed by a uniquely constructed housing (32). The housing (32) defines a free convection air channel below the screen (30) to conduct a cooling air flow. The air flow in the free convection air channel substantially eliminates the problem of image deterioration due to screen overheating.

Abstract: A liquid crystal display panel projector including a housing having a thermally isolated hot compartment which has an illumination source and a cold compartment which retains liquid crystal display panel. The housing includes individual cooling fluid paths for the hot and cold compartments. The display panel is disposed in the cold compartment where it is isolated from the thermal energy of the illumination source to provide a substantially stable thermal environment.

Abstract: The present invention concerns a projection pad using a liquid crystal panel in which a transmission type liquid crystal panel is placed between a light source and a screen, and an image displace on the surface of the liquid crystal panel is displayed on a screen. In this type of the projection pad, energy of light projected from the light source is partially converted into heat energy at the inside of the projection pad, which increases the temperature of the projection pad thereby causing disadvantage such as liquefication of liquid crystals, abnormal operation of the panel controlling circuit, etc. It is, accordingly, necessary to provide an appropriate cooling mechanism to the inside of the projection pad. In the present invention, the structure of the cooling mechanism is adapted such that sufficient cooling effect can be obtained by an axial flow blower small in the size and reduced in the thickness thereby enabling to reduce the size and decrease the thickness of the projection pad itself.

Abstract: A presentation device for an overhead projector of this invention includes a frame-shaped casing, a transmissive-type liquid crystal panel fixed in the casing, first and second protective covers mounted on the casing to have predetermined gaps from the liquid crystal panel and to cover both surfaces of the liquid crystal panel, and exhaust fans disposed in the casing. In order to detachably mount the first and second protective covers to the casing, locking pawls and locking pieces which can be elastically deformed are formed on the outer edges of the first and second protective covers, and the notches and fitting holes to which the locking pawls and the locking pieces can be respectively fitted are formed in the casing.

Abstract: An image projector is provided with increased light magnification through lenses positioned between the light source and the platen section of the projector. In addition to increased light magnification, increased image magnification is provided between the platen section and the mirror. Cooling air is directed separately over the light source and exhausted separately to dissipate additional heat generated with the increased magnification of light upstream and downstream from the platen section. The increased magnification and cooling air allows the clear projection of delicate items, such as photographs, which are otherwise not projectable by prior projectors.

Abstract: An overhead projector comprises a flat base accommodating a reflective Fresnel lens below a writing surface. A hollow arm projecting up from one side of the base supports a projection head comprising a light source, an objective lens assembly spaced horizontally from the light source, a first deflection mirror for directing rays from the light source down onto the writing surface and reflective Fresnel lens and a second deflective lens for directing rays from the writing surface and reflective Fresnel lens out through the objective lens assembly. The objective lens assembly is tiltable to direct light rays on an upwardly inclined path and the second deflection mirror is also tiltable and is coupled with the objective lens assembly so as to be tilted half as much as the objective lens assembly.

Abstract: A thermal management system particularly adapted for a portable lightweight opaque projector dissipates the heat generated within the projector by the projector light source in a controlled fashion, while maintaining the exterior of the projector in a moderate temperature range. Opposed sidewalls of the enclosed interior illumination chamber of the projector are provided with alongated planar heat sink surfaces which are coated with a flat black finish which is highly absorptive of infrared as well as visible radiation. The heat sink surfaces are mounted spaced from the adjacent interior sidewall of the projector, such that an air channel or plenum is formed between the heat sinks and the adjacent sidewall. Exhaust fans draw air out from the interior of the projector and through these air channels to thereby remove heat absorbed by the heat sinks. The exterior sidewalls of the projector opposite the heat sinks are provided with a passive heat dissipation mechanism.

Abstract: A cooling device is provided for a light source in a copying machine, wherein the generation of air seemingly waving due to heat is prevented by effectively cooling a lamp body for lighting an original effectively in order to obviate the deterioration of an optical image.Light pervious heat-shield members are disposed at suitable intervals in an irradiation opening of the lamp body accommodating light source bulb and a reflector therewithin so as to enable blowing of ambient air past and between these members. At least the member positioned at the side of the light source bulb is composed of a heat-ray absorption glass. Air flow is guided through the chamber accommodating the light source bulb so that it may perform a forced air cooling of the inside of the lamp body in order to prevent the generation of the air waving due to heat from the lamp.

Abstract: An image projector has a pulsed or similar light source of high intensity and high heat emission housed in an opaque box having a light-diffusing glass panel in its forward side which is spaced behind a vacuum film-holding plate having a glass center. Between the box light and the film-holding plate is a compartment which is open on the front and back and is sandwiched between the light diffusing glass panel of the box light and the film-holding plate such that no light escapes into the room. Said compartment thus comprises an isolation chamber which passes light to the film but not heat. The box light and the isolation chamber each has its own blower system and independent, specially baffled vents such that air between the two does not intermix. The vents are so designed as to permit discharge of the air but inhibit the egress of light therethrough.

Abstract: A projection display device projector capable of improving cooling efficiency of the power unit includes a light source lamp unit, a projection lens unit, an exhaust fan provided near the light source lamp unit for ventilating an outer case, and a ventilating path provided inside the power unit. A suction fan is provided at the inlet of the ventilating path which is connected to the cooling air intake port through a duct cover to directly conduct fresh air into the ventilating path. Because the interior of the power unit is cooled by fresh air which is cooler than the air inside the outer case, cooling efficiency is enhanced.