Image capturing array system and fingerprint identification device

1. An image capturing array system comprising, in order from an object side to an image side:

at least two image lens units, and

at least one image sensor disposed on an image plane of each of the image lens units;

wherein each of the image lens units comprises at least one lens element with refractive power, an object-side surface and an image-side surface of the lens element are aspheric, and an object is relatively stationary with respect to the image lens units during an image capturing process;

wherein in each of the image lens units, an object height of the image lens unit is YOB, an image height of the image lens unit is YRI, the lens element which is closest to the object is an first lens element, an axial distance between the object and an object-side surface of the first lens element along an optical axis is OL, an axial distance between the object-side surface of the first lens element and the image plane along the optical axis is TL, a half of a maximal field of view of the image lens unit is HFOV, and the following conditions are satisfied:

2.0< YOB/YRI ; and

( OL+TL )/tan( HFOV )<5 mm.

2. The image capturing array system of claim 1 , comprising at least three image lens units, wherein the image lens units are arranged on a same plane as a two-dimensional array.

3. The image capturing array system of claim 2 , wherein the two-dimensional array is a matrix, a number of columns of the matrix is X, a number of rows of the matrix is Y, and the following conditions are satisfied:

2≦ X≦ 10; and

2≦ Y≦ 10.

4. The image capturing array system of claim 3 , wherein an image area of each of the image lens units is Ai, an overlapping image area between two of the image lens units is Aoi, and the following condition is satisfied:

( Aoi/Ai )×100%≦20%.

5. The image capturing array system of claim 3 , further comprising a hole piece with a two-dimensional through holes array arranged by a plurality of through holes, wherein each of the through holes is corresponded to each of the image lens units.

6. The image capturing array system of claim 5 , wherein each of the image lens units has at least one common element with a same functionality, and these common elements are formed into one unified piece.

7. The image capturing array system of claim 6 , wherein each of the image lens units has two or three lens elements with refractive power.

8. The image capturing array system of claim 6 , wherein in each of the image lens units, the image lens unit further comprises a stop, a focal length between an object and the stop is fF, a focal length between the stop and the image plane is fR, and the following condition is satisfied:

−1.0< fR/fF< 1.0.

9. The image capturing array system of claim 6 , wherein in each of the image lens units, the axial distance between the object and the object-side surface of the first lens element along the optical axis is OL, an axial distance between the object-side surface of the first lens element and the image plane along the optical axis is TL, and the following condition is satisfied:

OL+TL< 5 mm.

10. The image capturing array system of claim 6 , wherein in each of the image lens units, a minimal distortion of the image lens unit is DISTmin, and the following condition is satisfied:

−3.5%<DISTmin.

11. The image capturing array system of claim 6 , wherein in each of the image lens units, an f-number of the image lens unit is Fno, the half of the maximal field of view of the image lens unit HFOV, and the following conditions are satisfied:

4< Fno ; and

45 degrees< HFOV.

12. The image capturing array system of claim 6 , wherein in each of the image lens units, an image-side surface of the lens element which is closest to the image plane has at least one inflection point, a vertical distance between the inflection point on the image-side surface of the lens element and the optical axis is hp, the object height of the image lens unit is YOB, and the following condition is satisfied:

0 <hp/YOB< 0.3.

13. The image capturing array system of claim 1 , further comprising:

an image capturing window, the image capturing window is defined by an imaging area of the image capturing array system, a length of a minimal rectangular area circumscribing the image capturing window is L, a width of the minimal rectangular area circumscribing the image capturing window is W, and the following condition is satisfied:

0.5< L/W< 2.

14. The image capturing array system of claim 13 , wherein each of the image lens units has two or three lens elements with refractive power.

15. The image capturing array system of claim 14 , wherein in each of the image lens units, the axial distance between the object and the object-side surface of the first lens element along the optical axis is OL, an axial distance between the object-side surface of the first lens element and the image plane along the optical axis is TL, and the following condition is satisfied:

OL+TL< 5 mm.

16. The image capturing array system of claim 14 , wherein in each of the image lens units, a minimal distortion of the image lens unit is DISTmin, and the following condition is satisfied:

−3%<DISTmin.

17. The image capturing array system of claim 14 , wherein in each of the image lens units, an f-number of the image lens unit is Fno, the half of the maximal field of view of the image lens unit is HFOV, and the following conditions are satisfied:

4< Fno ; and

45 degrees< HFOV.

18. The image capturing array system of claim 14 , wherein in each of the image lens units, the image-side surface of the lens element which is closest to the image plane has at least one inflection point, a vertical distance between the inflection point on the image-side surface of the lens element and the optical axis is hp, the object height of the image lens unit is YOB, and the following condition is satisfied:

0< hp/YOB< 0.3.

19. A fingerprint identification device, comprising:

the image capturing array system of claim 1 ; and

a light source, the light source is disposed between the object and the image plane of each of the image lens units.

20. The fingerprint identification device of claim 19 , wherein a wavelength of the light source is λ, and the following condition is satisfied:

700 nm<λ<1000 nm.