An optical imaging system includes one or more lens surfaces divided into a plurality of areas, wherein adjacent areas among the plurality of areas are surfaces expressed by different equations, and light passing through each of the plurality of areas may be imaged on the image surface of the same image sensor. According to the disclosure, it is possible to form a composite lens surface by composing different shapes of curved surfaces on a lens surface constituting an optical imaging system and increase a design freedom of the optical imaging system. Further, it is possible to significantly improve optical characteristics of the optical imaging system, such as increasing the definition of image or the MTF property and the like. By applying plurality of such divided surface areas, it is also possible to optimize, synthesize, or manipulate the optical characteristics of the optical imaging system relevant to each interested field area.

An observation optical system for use in observing an image displayed on an image displaying surface, includes, in order from an observation surface side to the image displaying surface side: a first lens having a first transmission reflective surface and a first transmissive surface; and a second lens having a second transmission reflective surface and a second transmissive surface, in which the first lens and the second lens are arranged via an interval interposed therebetween; light from the image displaying surface transmits through the second lens, is reflected by the first transmission reflective surface, is reflected by the second transmission reflective surface, is transmitted through the first lens, and then travels toward the observation surface side; and a focal length of the first lens and a focal length of the observation optical system are appropriately set.

A photographing lens system includes, in order from an object side to an image side along an optical path, a front lens group and a rear lens group. The front lens group includes four lens elements. The rear lens group includes four lens elements. A second lens element counted from the image side in the front lens group has negative refractive power. An image-side surface of a first lens element counted from the image side in the front lens group is convex in a paraxial region thereof. A second lens element counted from the object side in the rear lens group has negative refractive power. An object-side surface of a first lens element counted from the image side in the rear lens group is concave in a paraxial region thereof. At least one lens element in the rear lens group has at least one lens surface being aspheric.

An optical imaging lens, including a first lens element and a second lens element arranged in sequence from an object side to an image side along an optical axis. Each of the first lens element and the second lens element includes an object-side surface facing the object side and allowing imaging rays to pass through and an image-side surface facing the image side and allowing the imaging rays to pass through. An optical axis region of the image-side surface of the second lens element is concave, and a periphery region of the image-side surface of the second lens element is convex.

Single fold optical systems that include a power prism and a lens stack including two or more refractive lens elements. The single fold optical system may provide a long mechanical back focus without increasing the Z-height of the optical system. Providing power on the prism may reduce the optical total length and reduce the X-length of the optical system. The single folded optical systems may provide reduced Z-axis height and reduced X-axis length when compared to conventional double folded optical systems with similar optical characteristics. In addition, the optical systems may include an anamorphic lens that is oriented to correct for astigmatism caused by surface errors of the reflective surface of the prism.

The present disclosure relates to an imaging lens, a camera module and an electronic device including the same. The imaging lens according to an embodiment of the present disclosure includes a catadioptric lens on which light is incident from an object side, and through which light is reflected and emitted from the inside; and a lens group including a plurality of lenses for transmitting the light emitted from the catadioptric lens to an image surface, wherein the catadioptric lens includes: an incident surface on which light is incident from the object side; a second mirror surface which is formed concave toward the object side, and reflects the light incident on the incident surface to a first mirror surface in the object side; the first mirror surface which is formed, at a central portion of the incident surface, convex toward an image side, and reflects the light reflected from the second mirror surface toward the image side; and an exit surface through which the light reflected from the first mirror surface is emitted, wherein all of the lens group is disposed between the first mirror surface and the second mirror surface based on an optical axis. Accordingly, it is possible to increase the brightness of the lens, increase resolution, suppress an increase in thickness, and reduce tolerance due to mirror assembly.

A device includes a polarization non-selective partial reflector configured to transmit a first portion of a first light and reflect a second portion of the first light. The device also includes a polarization selective reflector configured to reflect the first portion of the first light received from the polarization non-selective reflector back to the polarization non-selective reflector. The device further includes a path correction device disposed between the polarization non-selective partial reflector and the polarization selective reflector, and configured to forwardly steer the first portion of the first light propagating between the polarization non-selective partial reflector and the polarization selective reflector.

An imaging lens set includes a plastic lens element. The plastic lens element having a central axis includes an object-side surface and an image-side surface, wherein the image-side surface is located opposite to the object-side surface. Each of the object-side surface and the image-side surface includes an effective optical section and a lens peripheral section in order from the central axis to an edge of the plastic lens element. The effective optical section is for being passed through by an imaging light and aspheric. The lens peripheral section surrounds the effective optical section. At least one of the lens peripheral section of the object-side surface and the lens peripheral section of the image-side surface includes at least one annular groove structure, wherein the annular groove structure includes a plurality of stepped surfaces and is not in contact with the optical elements.

The present invention relates to a reflective eyepiece optical system and a head-mounted near-to-eye display apparatus. The system includes: a first lens group, and a first optical element and a second lens group for transmitting and reflecting a light from a miniature image displayer. The second lens group includes an optical reflection surface, and the optical reflection surface is an optical surface farthest from a human eye viewing side in the second lens group. The optical reflection surface is concave to a human eye viewing direction. The first optical element reflects the light refracted by the first lens group to the second lens group, and then transmits the light refracted, reflected, and refracted by the second lens group to the human eye.

An external lens for a mobile terminal includes a first lens group and a second lens group composed of cylindrical lenses arranged from an object side to an image side, the first lens group of light in the X direction The power of the second lens group in the X direction is greater than zero; the power in the Y direction of the external lens is zero. In this way, by using the unique optical characteristics of the cylindrical mirror, the horizontal field of view of the camera of the mobile terminal may be increased and the vertical field of view angle is not changed.