Abstract: A projector is provided with a housing including an air inlet and an air filter that covers the air inlet. The air filter is arranged on the housing. A clogging detection sensor detects a clogging degree of the air filter. A projection lens, which serves as a presentation unit displays the clogging degree of the air filter. A control unit displays the clogging degree with the projection lens in three or more stages based on the detection result of the clogging degree.

Abstract: A video projector includes an air inlet that draws in ambient air. An air filter device includes an air filter attached to the air inlet and performs a cleaning operation to remove dust from the air filter in accordance with a cleaning operation sequence. An intake fan draws in the ambient air through the air filter as cooling air for cooling a light valve. A lamp cooling fan sends interior air to a light source lamp as cooling air for cooling the light source lamp. A discharge fan discharges the interior air that has cooled the light source lamp or the light valve. The cleaning operation sequence is configured to perform the cleaning operation during a cooling operation period in which the intake fan is stopped after a projection operation ends while the lamp cooling fan and the discharge fan are operating to cool the light source lamp.

Abstract: When a dual-screen display mode is performed, two images based on two image signals, respectively, are simultaneously displayed in display regions of a display unit. If a presenter desires viewers to focus attention on one of the two images, a projector differentiates display manners of the images to be displayed, between one display region and the other display region. For example, if the presenter desires the viewers to focus attention on one image, the projector performs image processing for causing the other image to be displayed in an unhighlighted manner. As the image processing on this occasion, if the two images are both color images, the projector converts only the other image from the color image to a monochrome image.

Abstract: A shutter device can switch between a state where illuminating light from a lamp of an illuminating device is cut off (referred to as a closing state of the shutter device) and a state where illuminating light passes through (referred to as an opening state of the shutter device). A system control circuit instructs a lamp power source to decrease power supplied to the lamp, when receiving information indicating that the shutter device is in the closing state from the detecting portion. After receiving this instruction, the lamp power source decreases the power supplied to the lamp.

Abstract: A shutter device can switch between a state where illuminating light from a lamp of an illuminating device is cut off (referred to as a closing state of the shutter device) and a state where illuminating light passes through (referred to as an opening state of the shutter device). A system control circuit instructs a lamp power source to decrease power supplied to the lamp, when receiving information indicating that the shutter device is in the closing state from the detecting portion. After receiving this instruction, the lamp power source decreases the power supplied to the lamp.