BACKGROUND

1. Technical Field

The present disclosure relates to a light source device and a light-amount adjusting method.

2. Related Art

A technique of controlling output of respective light sources in a light source device including plural light sources that emit light having wavelengths different from one another by directly detecting leakage light from the light sources has been known (for example, WO2015/016172).

SUMMARY

In some embodiments, a light source device includes: a plurality of light sources configured to emit a plurality of kinds of light having wavelength band different from one another; a plurality of dichroic mirrors that are respectively arranged on a first optical path through which light is emitted to an outside, the plurality of dichroic mirrors having light transmission characteristics different from one another, each dichroic mirror being configured to reflect or pass light emitted from any one of the plurality of light sources; a plurality of light sensors that are respectively positioned on a plurality of second optical paths, each second optical path being a different optical path from the first optical path and being an optical path propagating light reflected on or passed through the dichroic mirror, each light sensor being configured to detect a light amount of light that propagates through the second optical path; and a controller configured to control a light amount ratio of the plurality of kinds of light based on the light amount respectively detected by the plurality of light sensors.

In some embodiments, a light source device includes: a first light source configured to emit light of a first wavelength band; a second light source configured to emit light of a second wavelength band; a first dichroic mirror that is arranged on a first optical path through which light is emitted to an outside of the light source device, the first dichroic mirror being configured to reflect or pass light emitted from the first light source; a second dichroic mirror that is arranged on the first optical path on a side of an emitting position of light to the outside relative to the first dichroic mirror, the second dichroic mirror having a light transmission characteristic different from the first dichroic mirror, the second dichroic mirror being configured to separate light emitted from the second light source to a component traveling to the first optical path and a component traveling to a second optical path different from the first optical path, the second dichroic mirror being configured to reflect a part of light from the first light source, which is reflected on the first dichroic mirror, toward the second optical path; and a light sensor unit that is positioned on the second optical path, the light sensor unit being configured to detect a light amount of light propagating through the second optical path. The light sensor unit includes a first light sensor to detect the light of the first wavelength band, and a second light sensor to detect the light of the second wavelength band, the first light sensor and the second light sensor are arranged at positions that are determined based on a spectral sensitivity characteristic, a maximum light amount according to a wavelength of incident light, and a light intensity distribution, the first light sensor includes at least two light sensors that are arranged at positions at which illumination intensities differ from each other in the light sensor unit, the second light sensor includes at least two light sensors that are arranged at positions at which illumination intensities differ from each other in the light sensor unit, and the light of the first wavelength band and the light of the second wavelength band are subjected to light amount detection in a dynamic range wider than a case of a single light sensor, by combining detection values of at least two light sensors.

In some embodiments, a light-amount adjusting method includes: emitting each of a plurality of kinds of light having wavelength band different from one another by a plurality of light sources; reflecting light emitted from a light source to a first optical path through which light is emitted to an outside, with a plurality of dichroic mirrors; passing the light emitted from the light source to a second optical path that is different from the first optical path, with the plurality of dichroic mirrors; detecting a light amount of light that has passed through the plurality of dichroic mirrors with a light sensor; and controlling a light amount ratio of the plurality of kinds of light based on the light amount detected by the light sensor, with a controller.

The above and other features, advantages and technical and industrial significance of this disclosure will be better understood by reading the following detailed description of presently preferred embodiments of the disclosure, when considered in connection with the accompanying drawings.

