Light source device having ring-like blocking portion
A light source device includes: a first and second light sources respectively emitting a first and second light beams spectra of which are different from each other; an element guiding the first and second light beams to a common optical path; a first and second sensors respectively detecting light quantities of the first and second light beams; and a controller controlling, on the basis of the detected light quantities, the light quantities of the first and second light beams. The element guides the first light beam to the path by reflecting the first light beam, the first sensor is disposed in the path, the device further includes a first and second members respectively blocking a first and second regions respectively corresponding to portions of the first and second light beams, the first sensor is disposed in the second region, and the second sensor is disposed in the first region.
1 . A light source device comprising:
a first light source configured to emit a first light beam;
a second light source configured to emit a second light beam, wherein a spectrum of the second light beam is different from a spectrum of the first light beam;
an optical-path conversion element that comprises a dichroic mirror and that respectively guides the first light beam and the second light beam to a common optical path;
a first sensor configured to detect a light quantity of the first light beam;
a second sensor configured to detect a light quantity of the second light beam; and
a controller comprising hardware, the controller being configured to control, based on the light quantity detected by the first sensor and the light quantity detected by the second sensor, the light quantity of the first light beam of the first light source and the light quantity of the second light beam of the second light source, wherein
the optical-path conversion element guides the first light beam to the common optical path by reflecting the first light beam,
the first sensor is disposed in the common optical path,
the light source device further comprises:
a first blocking member that is disposed between the first light source and the optical-path conversion element and that blocks a first blocked region, which is a region corresponding to a portion of the first light beam; and
a second blocking member that is disposed between the second light source and the optical-path conversion element and that blocks a second blocked region, which is a region corresponding to a portion of the second light beam,
the first sensor is disposed in the second blocked region, and
the second sensor is disposed in the first blocked region.
2 . The light source device according to claim 1 , further comprising:
a limiting member that is disposed in the common optical path;
a first collimating element that is disposed between the first light source and the limiting member and that converts the first light beam to a collimated light beam having a first diameter; and
a second collimating element that is disposed between the second light source and the limiting member and that converts the second light beam to a collimated light beam having a second diameter, wherein
the limiting member has an opening having a smaller diameter than the first diameter and the second diameter and limits passage of the first light beam and the second light beam to only the opening,
the first sensor detects, of the first light beam, a light quantity of a portion thereof that does not pass through the opening, and
the second sensor detects, of the second light beam, a light quantity of a portion thereof that does not pass through the opening.
3 . The light source device according to claim 2 , wherein each of the first collimating element and the second collimating element comprises a lens.
4 . The light source device according to claim 2 , wherein the limiting member is an aperture stop.
5 . The light source device according to claim 1 , wherein:
the optical-path conversion element guides the second light beam to the common optical path by allowing the second light beam to pass through the optical-path conversion element; and
the second sensor is disposed in the common optical path.
6 . The light source device according to claim 1 , further comprising:
a third light source that emits a third light beam, wherein a spectrum of the third light beam is different from the spectrum of the first light beam and the spectrum of the second light beam;
a third sensor that is disposed in the common optical path and that detects a light quantity of the third light beam; and
a third blocking member that is disposed between the third light source and the optical-path conversion element and that blocks a third blocked region, which is a region corresponding to a portion of the third light beam, wherein
the optical-path conversion element guides the third light beam to the common optical path by allowing the third light beam to pass through the optical-path conversion element,
the first sensor is disposed in a region in which all of blocked regions excluding the first blocked region overlap with each other,
the second sensor is disposed in a region in which all of the blocked regions excluding the second blocked region overlap with each other, and
the third sensor is disposed in a region in which all of the blocked regions excluding the third blocked region overlap with each other.
7 . The light source device according to claim 6 , wherein:
the third blocking member is a ring-like member;
the third blocking member has a ring-like or partially ring-like blocking portion and a passage that is provided in a portion in a circumferential direction of the third blocking member and that allows the third light beam to pass through the passage.
8 . The light source device according to claim 1 , wherein:
each of the first blocking member and the second blocking member is a ring-like member;
the first blocking member has a ring-like or partially ring-like blocking portion and a first passage that is provided in a portion in a circumferential direction of the first blocking member and that allows the first light beam to pass through the first passage, and
the second blocking member has a ring-like or partially ring-like blocking portion and a second passage that is provided in a portion in a circumferential direction of the second blocking member and that allows the second light beam to pass through the second passage.