Abstract: An endoscope optical system includes, in order from an object side: a fixed negative first lens group; a movable positive second lens group; a fixed aperture stop; and a fixed positive third lens group, the endoscope optical system being capable of switching between a normal observation state and a magnified observation state by moving the second lens group along an optical axis, in which the third lens group includes, in order from the object side: a cemented lens consisted of three lenses; and a cemented lens consisted of two lenses. In the cemented lens consisted of three lenses, three lenses of a positive lens, a negative lens, and a positive lens are cemented. In the cemented lens consisted of two lenses, two lenses of a positive lens and a negative lens are cemented. The following conditional expressions (1) and (2) are satisfied: 1.70<(nd3G1+nd3G2+nd3G3)/3<2.0 (1); and 1.72<(nd3G4+nd3G5)/2<2.0 (2).

Abstract: An endoscope includes a plurality of illuminating optical systems, an objective optical system, and an optical-path splitting member. The optical-path splitting member has an optical element which forms a first optical path and a second optical path, and an optical-path length of the first optical path differs from an optical-path length of the second optical path. Illumination light is irradiated to an object from the plurality of illuminating optical systems. The objective optical system has an object-side incidence surface which is located nearest to the object, and each of the plurality of illuminating optical systems has an object-side emergence surface which is located nearest to the object. Each of the object-side emergence surfaces is located on an image side of the object-side incidence surface, and following conditional expression (1) is satisfied: 2.0<Dmin/OPLdiff<50??(1).

Abstract: An endoscope apparatus including a connector included in an endoscope and connected to an endoscope connection portion of a video processor, a fluid feeding apparatus including a tube configured to transmit fluid to the endoscope, a connection detector configured to detect a connection state of the tube with the connector of the endoscope, a control unit configured to detect an ON/OFF state of a power source of the fluid feeding apparatus, determine an abnormality exists when the connection detector detects that the tube is in a disconnected state with the connector of the endoscope and the power source of the fluid feeding apparatus is detected to be in an ON state, and output a notification of the determined abnormality, and a display configured to display the notification of the abnormality outputted by the control unit.

Abstract: An endoscope includes a plurality of illuminating optical systems, an objective optical system, and an optical-path splitting member. The optical-path splitting member has an optical element which forms a first optical path and a second optical path, and an optical-path length of the first optical path differs from an optical-path length of the second optical path. Illumination light is irradiated to an object from the plurality of illuminating optical systems. The objective optical system has an object-side incidence surface which is located nearest to the object, and each of the plurality of illuminating optical systems has an object-side emergence surface which is located nearest to the object. Each of the object-side emergence surfaces is located on an image side of the object-side incidence surface, and following conditional expression (1) is satisfied: 2.0<Dmin/OPLdiff<50??(1).

Abstract: An endoscope optical system includes, in order from an object side: a fixed negative first lens group; a movable positive second lens group; a fixed aperture stop; and a fixed positive third lens group, the endoscope optical system being capable of switching between a normal observation state and a magnified observation state by moving the second lens group along an optical axis, in which the third lens group includes, in order from the object side: a cemented lens consisted of three lenses; and a cemented lens consisted of two lenses. In the cemented lens consisted of three lenses, three lenses of a positive lens, a negative lens, and a positive lens are cemented. In the cemented lens consisted of two lenses, two lenses of a positive lens and a negative lens are cemented. The following conditional expressions (1) and (2) are satisfied: 1.70<(nd3G1+nd3G2+nd3G3)/3<2.0 (1); and 1.72<(nd3G4+nd3G5)/2<2.0 (2).

Abstract: The endoscope optical system includes in order from an object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a third lens group having a positive refractive power. Switching between a normal observation and a magnified observation is possible by fixing the first lens group and the third lens group, and moving the second lens group. The third lens group includes a cemented lens. The cemented lens includes an object-side lens and an image-side lens, and the following conditional expressions (1) and (2) are satisfied: 0.471<nd02?nd01<0.475??(1) 52.6<vd01?vd02<53??(2).

Abstract: This endoscope objective optical system is capable of acquiring images of high resolution and wide angle of observation field, maintaining low invasiveness and appropriately correcting various aberrations. This optical system has at least a first cemented lens which has a positive lens and a negative lens, in which the cemented lens satisfies the following conditional expressions: (1) 15.0<?A?ndA<15.75 and (2) ?0.2>rdyA1/ih>?20, wherein ?A is an Abbe number of the negative lens, ndA is a refractive index of the negative lens at the d-line, rdyA1 is a curvature radius of a joining surface of the negative lens, and ih is an image height.

Abstract: An endoscope apparatus including a connector included in an endoscope and connected to an endoscope connection portion of a video processor, a fluid feeding apparatus including a tube configured to transmit fluid to the endoscope, a connection detector configured to detect a connection state of the tube with the connector of the endoscope, a control unit configured to detect an ON/OFF state of a power source of the fluid feeding apparatus, determine an abnormality exists when the connection detector detects that the tube is in a disconnected state with the connector of the endoscope and the power source of the fluid feeding apparatus is detected to be in an ON state, and output a notification of the determined abnormality, and a display configured to display the notification of the abnormality outputted by the control unit.

Abstract: An endoscope system includes an objective optical system, an optical-path splitter which acquires two optical images with different focus, an image sensor which acquires the optical images. The objective optical system includes a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a third lens group having a positive refractive power. Switching to a normal observation and a close observation is possible by moving the second lens group toward an image side. The first lens group includes a first lens having a negative refractive power, and at least one positive lens, and the following conditional expressions (1)??, (2), and (3)?? are satisfied: 1.40?D_2T/fw<5 ??(1)?? 1.01<?(wide)/?(tele)<3.0 ??(2) 2.70?D_1G/D_2T<3.21 ??(3)??.

Abstract: The endoscope optical system includes in order from an object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a third lens group having a positive refractive power. Switching between a normal observation and a magnified observation is possible by fixing the first lens group and the third lens group, and moving the second lens group. The third lens group includes a cemented lens. The cemented lens includes an object-side lens and an image-side lens, and the following conditional expressions (1) and (2) are satisfied: 0.471<nd02?nd01<0.475 ??(1) 52.6<vd01?vd02<53 ??(2).

Abstract: This endoscope objective optical system is capable of acquiring images of high resolution and wide angle of observation field, maintaining low invasiveness and appropriately correcting various aberrations. This optical system has at least a first cemented lens which has a positive lens and a negative lens, in which the cemented lens satisfies the following conditional expressions: (1) 15.0<?A?ndA<15.75 and (2) ?0.2>rdyA1/ih>?20, wherein ?A is an Abbe number of the negative lens, ndA is a refractive index of the negative lens at the d-line, rdyA1 is a curvature radius of a joining surface of the negative lens, and ih is an image height.

Abstract: This endoscope objective optical system is capable of acquiring images of high resolution and wide angle of observation field, maintaining low invasiveness and appropriately correcting various aberrations. This optical system has at least a first cemented lens which has a positive lens and a negative lens, in which the cemented lens satisfies the following conditional expressions: (1) 15.0<?A?ndA<15.75 and (2) ?0.2>rdyA1/ih>?20, wherein ?A is an Abbe number of the negative lens, ndA is a refractive index of the negative lens at the d-line, rdyA1 is a curvature radius of a joining surface of the negative lens, and ih is an image height.

Abstract: An endoscope system includes an objective optical system OBL, an optical path splitting unit which splits an object image acquired by the objective optical system OBL into two optical images having a different focus, an image pickup element which acquires the optical images, and an image synthesis processing section which selects in a predetermined area an image with a relatively high contrast from the two optical images acquired, and generates a composite image, wherein the objective optical system OBL includes a first lens L1 having a negative refractive power which is nearest to object, and the endoscope system satisfies the following conditional expressions (1) and (2). 3<D_diff/im_pitch?100??(1) 0.005<D_diff/R1_r<1.

Abstract: This endoscope has an observation optical system that switches its observation mode between magnified observation and normal observation by moving some lenses in an optical-axis direction; and a plurality of illumination optical systems, wherein lens surfaces at the most distal ends of the plurality of illumination optical systems are disposed closer to a proximal end than a lens surface at the most distal end of the observation optical system, and all of the lens surfaces at the most distal ends of the plurality of illumination optical systems are disposed substantially parallel to the lens surface at the most distal end of the observation optical system, wherein the following conditional expressions (1) to (3) are satisfied. 1.0?D_Back(far)/D_Back(near)<3.0??(1) 0.015<D_Back(far)/D_far<1.0??(2) 1.01<?(wide)/?(tele)<5.

Abstract: An optical measuring device includes: a light source unit; a measurement probe including a fiber bundle, an illumination fiber that illuminates a living tissue with a illumination light, and a plurality of light-receiving fibers that receives return light of the illumination light reflected and/or scattered at the living tissue; a detection unit that receives the return light of the illumination light detected by the plurality of respective light-receiving fibers, and performs photoelectric conversion to detect respective signal intensities; and an association unit that associates the respective signal intensities detected by the detection unit with distances from the illumination fiber to the respective light-receiving fibers on an end face of a distal end portion of the measurement probe, when light having an intensity gradient around the illumination fiber is projected to the end face of the distal end portion of the measurement probe.

Abstract: This endoscope includes an observation optical system capable of changing a magnified observation and a normal observation with each other, and a plurality of illumination optical systems, wherein a most tip side lens surface of at least one of the illumination optical systems is disposed at a position which is closer to a proximal end side than a most tip side lens surface of the observation optical system, and the following conditional expressions are satisfied. 0.03<D_Back(max)/ft<2??(1) 1.05<ft/fw<5??(2) In the expression, D_Back(max) is a maximum value of a distance between the most tip side lens surface and the most tip side lens surface, ft is a focal length in a close-distance magnified observation state, and fw is a focal length in a normal observation state.

Abstract: To off-axis and on-axis aberrations at low cost while having a wide angle of view, an endoscope objective optical system (1) has in order: a negative first lens (L1); a negative second lens (L2) and a third lens (L3) joined to each other; a brightness diaphragm (S); and a positive lens group (G2) having a cemented lens (CL2) including one positive lens and one negative lens joined to each other, and satisfies expressions (1) and (2): 1.0<D3(96 deg)/f_all<10??(1) 1.1<(r1+r2)/(r1?r2)<5.0??(2) where, D3(96 deg) is a distance in which a chief ray of a d-line having an incident angle of 96 degrees that enters the first lens transmits the third lens, f_all is a focal distance of the whole system, r1 and r2 are radii of curvature of an object side surface of the first lens and an image side surface of the second lens, respectively.

Abstract: This endoscope has an observation optical system that switches its observation mode between magnified observation and normal observation by moving some lenses in an optical-axis direction; and a plurality of illumination optical systems, wherein lens surfaces at the most distal ends of the plurality of illumination optical systems are disposed closer to a proximal end than a lens surface at the most distal end of the observation optical system, and all of the lens surfaces at the most distal ends of the plurality of illumination optical systems are disposed substantially parallel to the lens surface at the most distal end of the observation optical system, wherein the following conditional expressions (1) to (3) are satisfied. 1.0?D_Back(far)/D_Back(near)<3.0??(1) 0.015<D_Back(far)/D_far<1.0??(2) 1.01<?(wide)/?(tele)<5.

Abstract: There is provided an endoscope system in which a depth of field is widened, and which is capable of acquiring a high-quality image with an aberration corrected favorably. The endoscope system includes an objective optical system OBL, an optical path splitting unit which splits an object image acquired by the objective optical system OBL into two optical images having a different focus, an image pickup element which acquires the optical images, and an image synthesis processing section which selects in a predetermined area an image with a relatively high contrast from the two optical images acquired, and generates a composite image, wherein the objective optical system OBL includes a first lens L1 having a negative refractive power which is nearest to object, and the endoscope system satisfies the following conditional expressions (1) and (2). 3<D_diff/im_pitch?100??(1) 0.005<D_diff/R1_r<1.

Abstract: This endoscope includes an observation optical system capable of changing a magnified observation and a normal observation with each other, and a plurality of illumination optical systems, wherein a most tip side lens surface of at least one of the illumination optical systems is disposed at a position which is closer to a proximal end side than a most tip side lens surface of the observation optical system, and the following conditional expressions are satisfied. 0.03<D_Back(max)/ft<2??(1) 1.05<ft/fw<5??(2) In the expression, D_Back(max) is a maximum value of a distance between the most tip side lens surface and the most tip side lens surface, ft is a focal length in a close-distance magnified observation state, and fw is a focal length in a normal observation state.