Abstract: An optical imaging system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens sequentially disposed in numerical order along an optical axis of the optical imaging system from an object side of the optical imaging system toward an imaging plane of the optical imaging system, wherein the first to seventh lenses are spaced apart from each other along the optical axis, and the optical imaging system satisfies 0.4 < L1TR/L7TR < 1.9, where L1TR is an overall outer diameter of the first lens, L7TR is an overall outer diameter of the seventh lens, and L1TR and L7TR are expressed in a same unit of measurement.

Abstract: An optical imaging system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens sequentially disposed in numerical order along an optical axis of the optical imaging system from an object side of the optical imaging system toward an imaging plane of the optical imaging system, wherein the first to seventh lenses are spaced apart from each other along the optical axis, and the optical imaging system satisfies 0.4<L1TR/L7TR<1.9, where L1TR is an overall outer diameter of the first lens, L7TR is an overall outer diameter of the seventh lens, and L1TR and L7TR are expressed in a same unit of measurement.

Abstract: An optical imaging system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens sequentially disposed from an object side. The optical imaging system satisfies |Pnu| [10?6° C.?1 mm?1]?30, where Pnu is ?Pnui in which i=1, 2, . . . , 7, Pnui is 1/(vti·fi), vti is [DTni/(ni?1)?CTEi]?1, fi is an effective focal length of an i-th lens, ni is a refractive index of the i-th lens, DTni is a rate (dni/dT) of change of the refractive index according to a temperature of the i-th lens, and CTEi is a thermal expansion coefficient of the i-th lens.

Abstract: An optical imaging system including a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens disposed in order from an object side, wherein one or more of the first to sixth lenses is disposed between a stop and an imaging plane and of those, one or more has positive refractive power and one is made of a glass material, and four or more of the first to sixth lenses are made of a plastic material.

Abstract: An optical imaging system including a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens disposed in order from an object side, wherein one or more of the first to sixth lenses is disposed between a stop and an imaging plane and of those, one or more has positive refractive power and one is made of a glass material, and four or more of the first to sixth lenses are made of a plastic material.

Abstract: An optical imaging system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens sequentially disposed in numerical order along an optical axis of the optical imaging system from an object side of the optical imaging system toward an imaging plane of the optical imaging system, wherein the first to seventh lenses are spaced apart from each other along the optical axis, and the optical imaging system satisfies 0.4<L1TR/L7TR<1.9, where L1TR is an overall outer diameter of the first lens, L7TR is an overall outer diameter of the seventh lens, and L1TR and L7TR are expressed in a same unit of measurement.

Abstract: An optical imaging system including a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens disposed in order from an object side, wherein one or more of the first to sixth lenses is disposed between a stop and an imaging plane and of those, one or more has positive refractive power and one is made of a glass material, and four or more of the first to sixth lenses are made of a plastic material.

Abstract: An optical imaging system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens sequentially disposed in numerical order along an optical axis of the optical imaging system from an object side of the optical imaging system toward an imaging plane of the optical imaging system, wherein the first to seventh lenses are spaced apart from each other along the optical axis, and the optical imaging system satisfies 0.4<L1TR/L7TR<1.9, where L1TR is an overall outer diameter of the first lens, L7TR is an overall outer diameter of the seventh lens, and L1TR and L7TR are expressed in a same unit of measurement.

Abstract: Provided is a flat panel display device. The flat panel display device includes a board unit having a board surface, and a display unit facing the board unit, the display unit having a second surface facing the board surface and a first surface opposite to the second surface and for allowing an image to be displayed thereon, wherein the display unit transmits external light through the first surface and the second surface, to allow the board surface to be seen through the first surface of the display unit.