An objective optical system for an endoscope consisting of, in order from an object side toward an image side: a front group having negative focal power; an aperture stop; and a rear group having positive focal power, wherein: the front group includes only three lenses, which consist of, in order from the object side toward the image side: a first lens having negative focal power; a second lens having negative focal power; and a third lens having positive focal power, the rear group includes only three lenses, which consist of, in order from the object side toward the image side: a fourth lens having positive focal power; a fifth lens having positive focal power; and a sixth lens having negative focal power, the second lens and the third lens are cemented to each other, and the fifth lens and the sixth lens are cemented to each other.

An endoscope includes in order from an object side, an objective optical system, an optical-path splitter, an image sensor, and an image processor. A λ/4 wavelength plate is disposed between the objective optical system and the splitter. The splitter includes first and second prisms, and has a beam splitting surface at which the first prism and the second prism are brought into close contact. The splitter splits light at the beam splitting surface, into a first optical path through which P-polarized light is transmitted and a second optical path through which S-polarized light is reflected. The first and second prisms are slid relative to one another along the beam splitting surface to adjust optical path lengths of the first and second optical paths, and are disposed at positions to cancel an amount of shift in focusing positions of extraordinary and ordinary light, and satisfy specific conditional expressions.

A control apparatus controls an operation of a self-propelled mechanism of an endoscope. The control apparatus includes a drive circuit that outputs a motor current, a motor current detection circuit that acquires a value relating to magnitude of the motor current as a detection value, a storage circuit that stores a limit value relating to the detection value, and a control circuit that performs an operation as a first controller that controls the drive circuit so as to stop the motor when it is determined that the detection value exceeds a value relating to the limit value, and performs an operation as a second controller that controls the drive circuit so as to stop the motor when it is determined that the detection value exceeds the value relating to the limit value.

The present technology relates to an imaging device and an electronic apparatus capable of adjusting a focus position and an image stabilization position with high accuracy. There are provided a lens that converges object light, an imaging element that photoelectrically converts the object light received from the lens, a circuit base that includes a circuit configured to output a signal received from the imaging element to an outside, an actuator that drives the lens with a PWM (Pulse Width Modulation) waveform in at least either one of an X-axis direction and a Y-axis direction, and plural detection units that are so disposed as to face plural first coils included in the actuator, and detect magnetic fields generated by the first coils. The present technology is applicable to an imaging device.

An image pickup device that is provided at a distal end portion of an insertion unit of an endoscope having a longitudinal axis, includes: a first lens barrel that houses a first optical system; a second lens barrel that is disposed on a proximal end side of the first lens barrel, houses a second optical system on which light having passed through the first optical system is to be incident, and includes a second lens barrel-distal end portion that is a distal end portion having a diameter smaller than a diameter of a first lens barrel-proximal end portion which is a proximal end portion of the first lens barrel; a sliding part that is provided around an outer peripheral surface of the second lens barrel-distal end portion and that is in contact with the first lens barrel-proximal end portion; and a pressing member that is externally fitted over the sliding part from the first lens barrel-proximal end portion. The pressing member includes a pressing member-inner peripheral surface that is in contact with both an outer peripheral surface of the first lens barrel-proximal end portion and an outer peripheral surface of the sliding part, and a movement restricting portion that restricts a movement of the sliding part in an axial direction of the longitudinal axis between the first lens barrel-proximal end portion and the movement restricting portion.

The present disclosure is directed to an optical adapter for an optical scope. The optical scope includes a tube defining a conduit. The optical adapter is coupled to an end of the tube. The optical adapter defines a proximate end and a distal end. The optical adapter includes a casing defining a longitudinal direction. The casing includes a first wall and a second wall, in which the first wall and the second wall define a first viewing port therebetween. The second wall defines a second viewing port. The optical adapter further includes a hinge coupled to the first wall, a reflecting lens defining a first end separated from a second end in the longitudinal direction, in which the first end is coupled to the hinge, and an actuator coupled to the first wall and to the second end of the reflecting lens. The actuator pivots the reflecting lens about the hinge from a retracted position adjacent to the first wall to an extended position toward the second wall.

An endoscope comprises a light splitting device for transmitting a first illuminating light and reflecting a second illuminating light emitted by a light source. The first illuminating light passes through a first color filter transmitting a first color. The second illuminating light passes through the second color filter transmitting a second color. The first color is different from the second color. The light splitting device combines a first incident light of the first color and a second incident light of the second color. The first incident light of the first color and the second incident light of the second color pass through an imaging lens and form images of the first color and the second color on an image sensor, respectively. A CFA (color filter array) comprising a plurality of first CFA components of the first color and a plurality of second CFA component of the second color covering the image sensor.

A relay optical system 20 for a rigid endoscope includes a lens fixing frame 21 and a plurality of lenses 22. The lens fixing frame 21 has a plurality of tubular bodies 26. The plurality of tubular bodies 26 are joined coaxially to each other. The plurality of lenses 22 are located at positions other than a joint position jp of the tubular bodies 26 in an axis direction of the lens fixing frame 21. The plurality of lenses 22 are located in the lens fixing frame 21 so as to have a coincident optical axis. The plurality of lenses 22 do not include a cemented lens.

Systems, methods, and devices for fluorescence imaging with a minimal area image sensor are disclosed. A system includes an emitter for emitting pulses of electromagnetic radiation and an image sensor comprising a pixel array for sensing reflected electromagnetic radiation, wherein the pixel array comprises active pixels and optical black pixels. The system includes a black clamp providing offset control for data generated by the pixel array and a controller comprising a processor in electrical communication with the image sensor and the emitter. The system is such that at least a portion of the pulses of electromagnetic radiation emitted by the emitter comprises electromagnetic radiation having a wavelength from about 770 nm to about 790 nm.

An optical unit includes a first lens, a second lens, and a holding member. The first lens is formed in a spherical segment having a first flat surface and a first convex spherical surface. The second lens is formed in a spherical segment having a second flat surface and a second convex spherical surface. A holding member has a first end portion that surrounds the first lens and a second end portion that surrounds the second lens. The holding member holds the first lens and the second lens with a frictional force such that the first convex spherical surface and the second convex spherical surface are adjacent to each other between the first end portion and the second end portion. The first end portion is located on the same surface as the first flat surface or closer to the second lens than the first flat surface. The second end portion is located on the same surface as the second flat surface or closer to the first lens than the second flat surface.