Collimated light generating apparatus

11061,244

16/083930

April 28, 2016

A lens (10) has an incidence surface (11) having a cylindrical shape and forming a concave shape, and an emitting surface (12) forming a convex shape with respect to an optical axis (10a). A light source (20) has a large divergence angle in a vertical direction, and a divergence angle in a horizontal direction which is smaller than that in the vertical direction. The light source (20) is located at a position of focal length of the lens (10) in the vertical direction on a side of the incidence surface. The horizontal direction of the light source (20) is aligned with a curvature direction of the cylindrical shape of the lens (10).

MITSUBISHI ELECTRIC CORPORATION (Tokyo, JP)

MITSUBISHI ELECTRIC CORPORATION (Tokyo, JP)

1. A collimated light generating apparatus comprising: a lens including both an incidence surface having a cylindrical concave shape, and an emergence surface having a convex shape axially symmetric with respect to an optical axis; and a light source such that divergence angle in a first direction in a plane perpendicular to the optical axis differs from divergence angle in a second direction different from the first direction by 90 degrees, wherein the light source is placed at a position of incidence-surface-side focal length for the second direction of the lens, and the first direction of the light source is aligned with curvature direction of the cylindrical shape of the lens, the radius of curvature (R h1) in the first direction of the incidence surface, the radius of curvature (R h2) in the first direction of the emitting surface, the thickness (d) of the lens, and the refractive index (n) of the lens are designed to satisfy the following relation: [mathematical expression included] and the focal length f for the second direction, the radius of curvature (R v1) in the second direction of the incidence surface, the radius of curvature (R v2) in the second direction of the emitting surface, and the thickness (d) of the lens, and the refractive index (n) of the lens are designed to satisfy the following relation: [mathematical expression included]

2. The collimated light generating apparatus according to claim 1 , wherein width of light emitting point of the light source is wider in the first direction than in the second direction.

3. The collimated light generating apparatus according to claim 1 , wherein the light source has astigmatic difference.

4. The collimated light generating apparatus according to claim 3 , wherein the light source is a semiconductor laser.

5. The collimated light generating apparatus according to claim 1 , wherein the light source has plural light emitting points in the first direction.

6. The collimated light generating apparatus according to claim 5 , wherein the light source is an array-type light source in which fill factor F.F., which is determined from both light emitting width W of each of the plural light emitting points and pitch P between the light emitting points, satisfies: 0.5≤F.F.<1.

7. The collimated light generating apparatus according to claim 5 , wherein the light source is a semiconductor laser array.

4323297 April 1982 Kawamura et al.
4621892 November 1986 Kataoka
5020888 June 1991 Ishibai et al.
5467335 November 1995 Braat
5680256 October 1997 Katsuma
6526089 February 2003 Haeno et al.
2009/0195849 August 2009 Ichii
2016/0057397 February 2016 Kurosaki
2016/0327906 November 2016 Futterer
2017/0170629 June 2017 Lerner
103176226 June 2013
0 617 461 December 1992
55-130512 October 1980
2-235010 September 1990
7-72311 March 1995
2725198 December 1997
2001-100145 April 2001
2002-22906 January 2002
2016-452302 April 2016

International Search Report issued in PCT/JP2016/063398 dated Jul. 19, 2016. cited by applicant
Japanese Office Action issued in Japanese Patent Application No. 2016-570056, dated Jan. 31, 2017. cited by applicant
Siegman, “Lasers”, University Science Books, Mill Valley, California, 1986, Total 18 pages. cited by applicant
European Office Action, dated Dec. 20, 2019, for European Apphcatton No. 16900479.3. cited by applicant
European Communication pursuant to Article 94(3) EPC dated Mar. 19, 2019 issued in the corresponding European Patent Application No. 16900479.3. cited by applicant
Office Action dated May 11, 2020 issued in the corresponding Chinese Patent Application No. 210680084699.1. cited by applicant

edspgr.11061244