Light source device, observation system, and color-balance correction method

An observation system comprising:

• a light source device;
• an imager that captures an image of a subject illuminated with illumination light output from the light source device and generates an image signal;
• an image processor configured to process the image signal;
• a storage;
• and
• a processor,
• wherein the light source device includes:
• a plurality of light sources that respectively output a plurality of light beams having different spectra from each other;
• a light output unit that comprises a hole and that externally outputs the illumination light generated from the plurality of light beams;
• at least one optical filter that has specific spectral transmission properties and through which at least one of the light beams output from at least one light source of the plurality of light sources travels;
• at least one temperature sensor that detects a current temperature of the at least one light source;
• and
• at least one light quantity sensor that detects a current light quantity of the at least one light beam before traveling through the optical filter,
• wherein the storage stores first correlation information and second correlation information about the at least one light source,
• wherein the first correlation information indicates a relationship between the temperature of the light source and spectral information about the light beam output from the light source,
• wherein the second correlation information indicates a relationship between the spectral information and a light quantity of the light beam at the light output unit,
• wherein the processor is configured to:
• calculate a variation in the spectral information about the at least one light beam based on the current temperature and the first correlation information;
• calculate a variation in the light quantity of the at least one light beam at the light output unit based on the variation in the spectral information and the second correlation information, the variation in the light quantity being caused by a change in the spectral information;
• and
• calculate a light-quantity correction amount for the at least one light source based on the variation in the light quantity and the current light quantity, and
• wherein the image processor configured to correct a signal value of each color in an image generated from the image signal based on the light-quantity correction amount.

A color-balance correction method for correcting a light quantity of a light beam output from a light source, wherein the light source is one of a plurality of light sources that respectively output a plurality of light beams having different spectra from each other, and the light beam output from the light source travels through at least one optical filter having specific spectral transmission properties, the color-balance correction method comprising:

• detecting a current temperature of the light source;
• detecting a current light quantity of the light beam before traveling through the at least one optical filter;
• calculating a variation in spectral information about the light beam based on the current temperature and first correlation information, the first correlation information indicating a relationship between the temperature of the light source and the spectral information about the light beam output from the light source;
• calculating a variation in a light quantity of the light beam after traveling through the at least one optical filter based on the variation in the spectral information and second correlation information, the variation being caused by a change in the spectral information, the second correlation information indicating a relationship between the spectral information about the light beam and the light quantity of the light beam after traveling through the at least one optical filter;
• and
• calculating a light-quantity correction amount for the light source based on the variation in the light quantity and the current light quantity.