Imaging lens and imaging apparatus using imaging lens
View Patent ↗Disclosed is an imaging lens having both high heat resistance that enables the imaging lens to be mounted on a printed circuit board by a reflow mounting method and a high optical performance. The imaging lens includes: a first positive lens group; a second negative lens group; a third positive lens group; and a fourth positive or negative lens group. Each of the first to fourth lens groups includes a parallel plane glass plate and a resin lens that has heat resistance and is arranged on the parallel plane glass plate so as to be integrated with the parallel plane glass plate.
1. An imaging lens comprising:
a first positive lens group in which a lens surface closest to an object side is a convex surface;
a second negative lens group in which a lens surface closest to an image side is a concave surface;
a third positive lens group in which a lens surface closest to the image side is a convex surface; and
a fourth positive or negative lens group in which a lens surface closest to the image side is a concave surface,
wherein the first to fourth lens groups are arranged in this order from the object side,
each of the first to fourth lens groups includes a parallel plane glass plate and a resin lens that has heat resistance and is arranged on the parallel plane glass plate so as to be integrated with the parallel plane glass plate.
2. The imaging lens according to claim 1 ,
wherein the first lens group includes a stop.
3. The imaging lens according to claim 1 ,
wherein the second lens group includes a stop.
4. The imaging lens according to claim 2 ,
wherein the lens group including the stop includes a filter having an infrared cut function.
5. The imaging lens according to claim 3 ,
wherein the lens group including the stop includes a filter having an infrared cut function.
6. The imaging lens according to claim 1 ,
wherein the imaging lens satisfies the following conditional expression:
0 <Tmp/Tmg< 1,
where Tmp indicates the average value of the thicknesses of the centers of all of the resin lenses in the first to fourth lens groups, and Tmg indicates the average value of the thicknesses of all of the parallel plane glass plates in the first to fourth lens groups.
7. The imaging lens according to claim 1 ,
wherein the second lens group satisfies the following conditional expression:
ν dg−νdp> 15
where νdp indicates the Abbe number of the resin lens with respect to the d-line, and νdg indicates the Abbe number of the parallel plane glass plate with respect to the d-line.
8. An imaging apparatus comprising:
the imaging lens according to claim 1 ; and
an imaging device that converts an optical image formed by the imaging lens into electric signals.