Patent 7997776 was granted and assigned to Denso on August, 2011 by the United States Patent and Trademark Office.
An indicating instrument for a vehicle has a display board and a light modulation member disposed to cover a surface of the display board. When a condition that an illumination intensity of the display board is lower than a threshold value has continued for a first time period, a light transmissivity of the light modulation member is controlled to a first level so that a driver can easily see the display board. When a condition that the illumination intensity of the display board is equal to or higher than the threshold value has continued for a second time period, the light transmissivity of the light modulation member is controlled to a second level that is lower than the first level to restrict entry of external light to the display board.