Patent ID: 9286860
Filing Date: 2016-03-15
CPC Classification: G09G,H05B

Claim Text:
1. An image display apparatus which displays an image comprising: a light source device which emits a source light; a light source control unit which controls a power supplied to the light source device; an image light emission unit which, utilizing the source light emitted from the light source device, emits an image light expressing the image; a light quantity measurement unit which measures a light quantity of the source light, the light quantity corresponding to a quantity of emitted light and having a whole range as the power supplied to the light source device is turned on and a voltage applied to the source light reaches a maximum level; 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 gradually decreasing the supplied power such that the light quantity of the source light gradually changes within a portion of a whole range of the light quantity, the light quantity measurement unit executes a second process of measuring the light quantity of the source light as the supplied power is gradually decreased in the first process, and acquiring light quantity data within the portion of the whole range of the light quantity, and the power/light quantity characteristic derivation unit executes a third process of deriving the power/light quantity characteristic by estimating the power/light quantity characteristic between a first value which is within the light quantity data acquired within the portion of the whole range and a second value which is within the whole range but which is not within the light quantity data acquired within the portion of the whole range, the estimation of the power/light quantity characteristic being based on the light quantity data acquired within the portion of the whole range of the light quantity in the second process and on the supplied power.