Patent ID: 8733946

Claim:
An image display apparatus which emits an image light expressing an image, and displays the image, the apparatus comprising: a light source device; a light source control unit which controls a power supplied to the light source device; an image light emission unit which, utilizing a source light emitted from the light source device, emits the image light; a light quantity measurement unit which measures a light quantity of the source light; a power/light quantity characteristic derivation unit which derives a power/light quantity characteristic indicating a relationship between the supplied power and the light quantity of the source light; and a light quantity adjustment unit which, based on the power/light quantity characteristic, adjusts the light quantity of at least one of the source light and the image light, wherein the light source control unit executes a first process of controlling the supplied power in such a way that the light quantity of the source light gradually decreases at a constant predetermined speed, the first process comprising a start-up process which is performed at a time that the image display apparatus is powered on and prior to displaying an image provided from an external instrument, the light quantity measurement unit executes a second process of measuring the light quantity of the source light while the source light is gradually changed in the first process, and acquiring light quantity data, and the power/light quantity characteristic derivation unit executes a third process of, based on the light quantity data acquired in the second process and on the supplied power, deriving the power/light quantity characteristic, wherein while the light source control unit executes the first process, the image light emission unit emits an image light expressing a start up screen which includes a start up image, and wherein the constant predetermined speed is gradually decreased over a period of time which is longer than a period of the first process during which the start up image is displayed.