Abstract: A projection display apparatus of the present invention includes: a lamp power controller 13 changing the value of power supplied to super-high pressure mercury lamp 21; atmospheric pressure sensor 61 detecting the atmospheric pressure around where projection display apparatus 1 is installed; and correlation table storage 53 in which information on power supplied to the light source, set up corresponding to atmospheric pressure is stored. Lamp power controller 13, based on the previously stored information on power supplied to super-high pressure mercury lamp 21, set up corresponding to the atmospheric pressure, controls the power supplied to super-high pressure mercury lamp 21 in accordance with the atmospheric pressure detected by atmospheric pressure sensor 61.

Abstract: A noise suppression characteristics adjustment method includes adjusting noise suppression characteristics of a noise suppressor, which includes a muffler having a reflection plate for reflecting sound from the cooling fan, the reflection plate being provided at a position in the cooling duct confronting an intake plane of the cooling fan and formed substantially parallel to the intake plane. A sound-absorbing part of the muffler is provided on the reflection plate. A distance d between the reflection plate and the intake plane is set such that d<c/(2×f) where f is a sound-absorption frequency of the muffler and c is a speed of sound. The muffler is located inside the cooling duct. A through-hole is provided in the reflection plate. The through hole includes a plurality of through-holes. A resonance frequency of the resonator sound absorber is adjusted by blocking at least one of the plurality of through-holes.

Abstract: An illuminating optical system for a projector including a light source and a plurality of display panels. The optical system includes a first integrator, which includes a plurality of lens cells that divide a luminous flux emitted by the light source into a plurality of partial luminous fluxes and that condense the respective partial luminous fluxes, a second integrator, which includes a plurality of lens cells on which the respective partial luminous fluxes are incident, a polarization converting element, which uniformizes polarizing directions of the luminous fluxes having passed through the respective lens cells of the second integrator, and a color separating unit, which separates each of the luminous fluxes from the polarization converting element into a plurality of color lights of different wavelengths. A field lens and a condenser lens are arranged between the polarization converting element and the color separating unit.

Abstract: The invention provides an illumination optical system that guides light emitted from light source device 1 to DMD 2, the illumination optical system including: light tunnel 20 that uniformizes luminance distribution of light emitted from light source device 1; relay optical system 40 that guides light having uniformized illumination distribution to DMD 2; and shield board 30 disposed on an optical path between light tunnel 20 and relay optical system 40. Shield board 30 is smaller than outlet end face 22 of light tunnel 20 and at the same time has an opening of a shape similar to the image formation area on DMD 2, and is movable in a plane containing the opening.

Abstract: A combined gear includes a pair of first gear and second gear having the same tooth profile and rotatably combined in a state, wherein rotation centers of the gears are coincident. One gear of the pair of gears includes an elastic displacement portion that is biased in a direction of rotating the other gear with respect to one gear. The other gear includes a positioning portion that positions the other gear with respect to one gear, and elastic displacement portion contacts positioning portion.

Abstract: The present invention includes: LCDs (47, 48, 49) corresponding to red, green, and blue, respectively; an air duct for red, an air duct for green, and an air duct for blue provided to blow cooling air to the LCDs (47, 48, 49), respectively; air filters (43, 50) provided in each of the air duct for red, the air duct for green, and the air duct for blue; and air filters (41, 42) provided in at least one air duct of the air duct for green and the air duct for blue and having filter mesh size smaller than that of the air filters (43, 50).

Abstract: A structure for connecting a display and a supporter, capable of supporting the display even if it is medium-sized or relatively large-sized, and being easily attached and detached. The structure has a structure for connecting the display and a supporter that is connected to the backside of the display and supports the display. The supporter has an upwardly fixed claw, a movable claw, and an operation unit for moving the movable claw. On the backside of the display are arranged an engagement hole with which the fixed claw engages and an engagement groove with which the movable claw engages.

Abstract: The present invention includes: a circuit board which is provided with an electronic circuit part; a first case and a second case (7) that cover the electronic circuit part; a fixing screw that fixes the first case and the second case (7); a tamper switch that outputs a signal indicating that the switch member is in a first state or second state; and a cap block (11) which is attached to the second case (7) so that the tamper switch keeps the first state only when the cap block (11) covers the fixing screw.