An observation condition acquisition unit acquires an observation condition including at least one of a moving speed of an endoscope, an observation distance between the endoscope and an observation target, or brightness of the observation target. A lesion information acquisition unit acquires lesion information including at least one of a diagnostic purpose or a certainty degree of a lesion obtained from an endoscope image at a timing at which the observation condition is acquired. A display format determination unit determines a display format of the lesion information on a display based on at least any of the observation condition or the lesion information. A control of displaying the lesion information on the display according to the display format is performed.

The endoscope objective optical system includes in order from an object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power. A lens surface positioned nearest to an image side in the second lens group is a concave surface which is directed toward the image side. The second lens group moves along an optical axis.

The objective lens unit includes, a front lens group having a negative refractive power, a diaphragm, and a rear lens group having a positive refractive power, in order from an object side. The front lens group includes a negative lens having a concave surface facing an image surface side, and a positive lens having a convex surface facing the object side, and the rear lens group includes a positive lens having a convex surface facing the image surface side and a cemented lens in which a positive lens and a negative lens are cemented. The endoscope objective lens unit satisfies −1.6<f.sub.F/f.sub.R<−1.2 and −1.3<f.sub.3/f.sub.F<−0.7. Note that f.sub.F and f.sub.R are focal lengths of the entire system of the front lens group and the rear lens group, and f.sub.3 is a focal length of a positive lens, in the rear lens group.

An endoscope may have a shaft having a distal end portion and a proximal end portion. The endoscope may also have a first objective arranged at the distal end portion and a first optical axis. The endoscope may also have a second objective arranged at the distal end portion and a second optical axis. The endoscope may also have a lens system disposed within the shaft between the distal end portion and the proximal end portion, the lens system having an optical axis. The first objective and the second objective may be both optically coupled to the same lens system such that first parallel rays from the first objective and second parallel rays from the second objective are input into the lens system. The lens system may be an optical relay system may have at least one relay group or a tube lens group.

An image processing apparatus includes a first acquisition unit that acquires a first pixel signal output from a first pixel, a second acquisition unit that acquires a second pixel signal output from a second pixel having a size smaller than that of the first pixel, a temperature detection unit that detects temperature; a composition gain determination unit that determines a composition gain corresponding to the detected temperature, and a composition unit that composes the first pixel signal and the second pixel signal multiplied by the composition gain.

An imaging optical system according to the present disclosure includes: an aperture stop; an image-forming optical system that causes an image to be formed toward an imaging plane of an image sensor; and an optical phase modulator that includes a substance having a birefringence index, and gives two pupil functions to the image-forming optical system. The following conditional expressions are satisfied:

1≤(2×L×tan(w)+D)/D<1.4   (1)

λ/4*0.75<Re<λ/4*1.1   (2), where L: a distance between the aperture stop and the optical phase modulator; D: an aperture diameter (diameter) of the aperture stop; w: a maximum angle of incidence of a principal light ray that enters the aperture stop; λ: a wavelength of light; and Re: phase retardation caused by birefringence of the optical phase modulator.

Provided is an endoscope having a tip at a distal section thereof, the tip includes a plurality of imaging units, at least one of the imaging units includes at least two optical lens assemblies and at least one optical sensor associated with the at least two optical lens assemblies, wherein each optical lens assembly has a different depth of field, thereby allowing to obtain a multi-focal image of a body cavity. Further provided are systems comprising the endoscope and methods of using the same in various endoscopic procedures.

A medical image processing device of the present disclosure includes: a division unit configured to divide at least one subject image in an image; a detection unit configured to detect a blur of the subject image divided by the division unit; a correction unit configured to correct the blur of the subject image based on the subject image divided by the division unit and the blur detected by the detection unit; and a combining unit configured to combine the subject image after correction and a background image formed by a region other than the subject image.

A focus control device includes a processor. The processor analyzes detection results of a target object in time sequence to determine whether the target object is in a lost state in which the target object is not temporarily captured into an image, sets a focus drive mode to an autofocus mode when the target object is detected, sets a first positional mode in which the focus lens is arranged at a position that is within a set range of an in-focus object plane position and is on the far point side of a central position when the target object is not detected and is not in the lost state, and sets the focus drive mode such that a lens position is nearer to a near point than in the first positional mode or sets the focus drive mode to the autofocus mode in a when the lost state is determined.

The invention relates to a subassembly (1) for an objective (10), in particular for a long and slim optical image transmission system, for example an endoscope, an objective (10) and an optical image transmission system, as well as methods for manufacturing a subassembly and an objective. The subassembly (1) comprises a prism (2) and an aperture element (3), wherein the prism (2) and the aperture element (3) are fixedly connected to each other, preferably by means of a putty or via direct bonding.