Optical imaging system
AssigneeSamsung Electro-Mechanics Co., Ltd.
InventorsKyu Min CHAE, Eun Chong LEE
Life of this patent
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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 ΣPnui 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.
Claims14
An optical imaging system comprising:
- a first lens having a negative refractive power;
- a second lens having refractive power;
- a third lens having a positive refractive power;
- a fourth lens having refractive power;
- a fifth lens having refractive power;
- a sixth lens having refractive power;
- and
- a seventh lens having refractive power,
- wherein the first to seventh lenses are sequentially disposed from an object side,
- wherein the third lens is comprised of glass, and
- wherein 0.2<DTnF/DTnR<0.6, where DTnF is a sum of DTn values of the first lens and the second lens, in which ΣDTni (i=1, 2), DTnR is a sum of DTn values of the third to seventh lenses, in which ΣDTni (i=3, 4, . . . , 7), and DTni is a rate (dni/dT) of change of the refractive index according to a temperature of the i-th lens.
Dependencies are inferred from the claim text.