An optical system for converting light from an object into parallel light, and guiding the parallel light to a plurality of image forming units each configured to form an image of the object includes a first lens unit having positive or negative refractive power and a second lens unit having positive refractive power that are disposed in order from an object side, wherein the first lens unit and the second lens unit are disposed at a widest interval in the optical system, and wherein the first lens unit consists of at least one positive lens and at least one negative lens that are disposed in order from the object side.

An objective optical system for an endoscope consisting of, in order from an object side toward an image side: a front group; and a rear group, wherein: the front group consists of, in order from the object side toward the image side: one negative lens; an optical path deflecting prism; an aperture stop; and one positive lens. The objective optical system for an endoscope satisfies a predetermined conditional expression.

An objective optical system for an endoscope consisting of, in order from an object side toward an image side: a front group; and a rear group, wherein: the front group consists of, in order from the object side toward the image side: one negative lens; an optical path deflecting prism; an aperture stop; and one positive lens. The objective optical system for an endoscope satisfies a predetermined conditional expression.

A camera module includes: a first refractive member configured to reflect or refract light that is incident on the first refractive member in a first direction, in a second direction intersecting the first direction; a second refractive member configured to reflect or refract the light that is reflected or refracted by the first refractive member and is incident on the second refractive member in the second direction, in a third direction intersecting the second direction; an image sensor configured to detect the light that is reflected or refracted by the second refractive member and is incident on the image sensor in the third direction; and at least one optical member provided between the first refractive member and the second refractive member, wherein the at least one optical member is configured to block the light that is reflected or refracted by the first refractive member from being incident on the image sensor, and to guide the light that is reflected or refracted by the first refractive member to be incident on the second refractive member in the second direction.

A camera module includes: a first refractive member configured to reflect or refract light that is incident on the first refractive member in a first direction, in a second direction intersecting the first direction; a second refractive member configured to reflect or refract the light that is reflected or refracted by the first refractive member and is incident on the second refractive member in the second direction, in a third direction intersecting the second direction; an image sensor configured to detect the light that is reflected or refracted by the second refractive member and is incident on the image sensor in the third direction; and at least one optical member provided between the first refractive member and the second refractive member, wherein the at least one optical member is configured to block the light that is reflected or refracted by the first refractive member from being incident on the image sensor, and to guide the light that is reflected or refracted by the first refractive member to be incident on the second refractive member in the second direction.

The present disclosure provides an optical imaging module, an optical imaging device and an electronic device. The optical imaging module includes a first lens group and a second lens group arranged in sequence from an object side to an imaging surface. The first lens group has a positive refractive power, and includes a first lens having a positive refractive power and a second lens having a negative refractive power arranged in sequence from the object side to the imaging surface. The first lens includes a convex object-side surface and a convex image-side surface. The second lens group includes a plurality of lenses with refractive power, and the plurality of lenses with refractive power include at least one movable lens configured to focus on objects to be photographed at different distances by moving along the optical axis.

The present disclosure provides an optical imaging module, an optical imaging device and an electronic device. The optical imaging module includes a first lens group and a second lens group arranged in sequence from an object side to an imaging surface. The first lens group has a positive refractive power, and includes a first lens having a positive refractive power and a second lens having a negative refractive power arranged in sequence from the object side to the imaging surface. The first lens includes a convex object-side surface and a convex image-side surface. The second lens group includes a plurality of lenses with refractive power, and the plurality of lenses with refractive power include at least one movable lens configured to focus on objects to be photographed at different distances by moving along the optical axis.

A removable camera lens attachment has at least two optical elements, wherein the at least two optical elements are aligned to share an optical axis with a prime lens of the camera. The lens attachment has at least two curved surfaces. The at least two optical elements have a first surface that is conditioned to reflect a first portion of the incident light away from the image plane as reflected stray light and a second surface that is conditioned to reflect a second portion of the reflected stray light back toward the image plane to form a ghost image on an image plane of the prime lens. The lens attachment alters the effective focal length of the prime lens by no more than 15%.

A removable camera lens attachment has at least two optical elements, wherein the at least two optical elements are aligned to share an optical axis with a prime lens of the camera. The lens attachment has at least two curved surfaces. The at least two optical elements have a first surface that is conditioned to reflect a first portion of the incident light away from the image plane as reflected stray light and a second surface that is conditioned to reflect a second portion of the reflected stray light back toward the image plane to form a ghost image on an image plane of the prime lens. The lens attachment alters the effective focal length of the prime lens by no more than 15%.

An imaging lens consists of: a first lens group having positive power, the first lens group including a positive lens closest to an object within the first lens group; an aperture stop; and a second lens group having positive power. The first lens group, the aperture stop, and the second lens group are disposed in that order from an object side toward an image side. Only two negative air lenses of a first biconvex air lens and a second biconvex air lens are provided within the imaging lens. The first lens group includes the first biconvex air lens, and the second lens group includes a second biconvex air lens.