An image display device that externally projects generated light and displays an image, the image display device comprising: a light source configured to generate the light; a light source drive unit configured to drive the light source and control a light quantity of the light; a reflecting mirror configured to reflect light generated at the light source and externally project the light, a direction to reflect the light being movable; a reflecting mirror drive unit configured to drive the reflecting mirror and control the direction to reflect the light; an image processing unit configured to process a first image signal externally inputted to the image display device to generate a second image signal, to supply and to control the second image signal for the image externally displayed to the light source drive unit, and to supply a synchronization signal for the second image signal to the reflecting mirror drive unit; an optical sensor configured to measure a light quantity of light generated at the light source and supply a measured value to the image processing unit; and a temperature sensor configured to measure a temperature of the light source and supply a measured temperature value to the image processing unit, wherein the image processing unit is configured to superpose, onto the second image signal to be supplied to the light source drive unit, a reference signal resulting in a reference light being generated at the light source, wherein a first measured value of the light quantity of the light generated at the light source being driven by the reference signal is obtained by the optical sensor when the light source drive unit drives the light source at a first measured temperature value; and wherein on the basis of a second measured value (L1') of the light quantity of the reference light measured at the optical sensor at a second measured temperature value of the light source which is different from the first measured temperature value, the image processing unit is configured to control the light source drive unit to adjust a current value to be supplied to the light source, so that the second measured value (L1') of the light quantity at the second measured temperature value comes close to the first measured value of the light quantity at the first measured temperature value as a target value; and the light source drive unit is configured to adjust a current amplification factor applied to the light source based on a temperature measured by the temperature sensor in order to correct for laser wavelength fluctuations. a light source configured to generate the light; a light source drive unit configured to drive the light source and control a light quantity of the light; a reflecting mirror configured to reflect light generated at the light source and externally project the light, a direction to reflect the light being movable; a reflecting mirror drive unit configured to drive the reflecting mirror and control the direction to reflect the light; an image processing unit configured to process a first image signal externally inputted to the image display device to generate a second image signal, to supply and to control the second image signal for the image externally displayed to the light source drive unit, and to supply a synchronization signal for the second image signal to the reflecting mirror drive unit; to process a first image signal externally inputted to the image display device to generate a second image signal, to supply and to control the second image signal for the image externally displayed to the light source drive unit, and to supply a synchronization signal for the second image signal to the reflecting mirror drive unit; an optical sensor configured to measure a light quantity of light generated at the light source and supply a measured value to the image processing unit; and a temperature sensor configured to measure a temperature of the light source and supply a measured temperature value to the image processing unit, wherein the image processing unit is configured to superpose, onto the second image signal to be supplied to the light source drive unit, a reference signal resulting in a reference light being generated at the light source, wherein a first measured value of the light quantity of the light generated at the light source being driven by the reference signal is obtained by the optical sensor when the light source drive unit drives the light source at a first measured temperature value; and wherein on the basis of a second measured value (L1') of the light quantity of the reference light measured at the optical sensor at a second measured temperature value of the light source which is different from the first measured temperature value, the image processing unit is configured to control the light source drive unit to adjust a current value to be supplied to the light source, so that the second measured value (L1') of the light quantity at the second measured temperature value comes close to the first measured value of the light quantity at the first measured temperature value as a target value; and the light source drive unit is configured to adjust a current amplification factor applied to the light source based on a temperature measured by the temperature sensor in order to correct for laser wavelength fluctuations.