Lens array, lens unit, led head, exposing unit, image forming apparatus, and image reading apparatus
View Patent ↗A lens array forms an erect image of an object. The lens array includes at least one row of lens elements and at least one rib. The lens elements are aligned in a first direction perpendicular to optical axes of the lens elements having an incidence surface and an exit surface. The rib is formed on the lens array and extending in a second direction parallel to the first direction and in a third direction parallel to the optical axes further than the incidence surface and the exit surface. A lens unit includes a shielding member and the lens array assembled to the shielding member. The shielding member includes diaphragms formed therein and aligned in a first direction, and a first engagement portion. The lens array includes a second engagement portion for engaging the first engagement portion to correct deformation of the lens array.
1. A lens array comprising:
at least one row of lens elements formed in a single piece structure aligned substantially in a first direction perpendicular to optical axes of the lens elements having an incidence surface and an exit surface;
at least one base portion extending in a second direction substantially perpendicular to the first direction and the optical axes and formed in a single piece structure with the lens elements; and
at least one rib formed on the at least one base portion, the at least one rib extending in a third direction substantially parallel to the first direction,
wherein the at least one rib extends in a fourth direction substantially parallel to the optical axes away from a first surface of the at least one base portion, and extends away in a fifth direction substantially parallel to the optical axes away from a second surface of the at least one base portion, the fourth direction being substantially opposite to the fifth direction.
2. A light emitting diode head incorporating the lens array according to claim 1 .
3. An exposing unit incorporating the lens array according to claim 1 .
4. An image forming apparatus incorporating the lens array according to claim 1 .
5. An image reading apparatus incorporating the lens array according to claim 1 .
6. A lens unit incorporating the lens array according to claim 1 , the lens unit comprising:
a shielding member including a plurality of diaphragms formed therein and aligned in a direction substantially perpendicular to the optical axes; and
two lens arrays, each being the lens array of claim 1 , the two lens arrays being mounted on the shielding member such that the diaphragms are located between two lens arrays, wherein the optical axes of the lens elements of one of the two lens arrays pass through corresponding diaphragms and are in line with optical axes of the lens elements of the other of the two lens arrays.
7. The lens array according to claim 1 , wherein the rib and the lens elements are formed in a single piece structure.
8. The lens array according to claim 1 , wherein the lens array is molded in a single piece structure.
9. The lens array according to claim 8 , wherein the lens array is injection-molded.
10. The lens array according to claim 1 , wherein the rib extends in the second direction further than the incident surface and the exit surface.
11. The lens array according to claim 1 , wherein the at least one base portion is a plurality of base portions and the at least one rib is one of a plurality of ribs that extend substantially in parallel to each other with the row being disposed between two adjacent ribs.
12. The lens array according to claim 11 , wherein the lens array has a substantially H-shaped cross-section taken in a plane substantially perpendicular to the first direction.
13. A lens unit incorporating the lens array according to claim 1 , comprising:
a shielding member including diaphragms formed therein and aligned in the first direction, the shielding member including in the first direction, the shielding member including an engagement portion,
wherein the lens array is mounted on the shielding member such that the engagement portion engages a portion of the lens array to hold the lens array in position.
14. An image reading apparatus incorporating the lens unit according to claim 1 .
15. A lens unit comprising:
a shielding member including diaphragms formed therein and aligned in a first direction, the shielding member including at least one pair of first engagement portions aligned in a second direction substantially parallel to the first direction and at least one second engagement portion extending in a third direction substantially parallel to the first direction, the at least one second engagement portion being located between the pair of first engagement portions;
a lens array mounted on the shielding member and including a plurality of lens elements aligned in a fourth direction substantially parallel to the first direction, the lens array including at least one pair of third engagement portions that engage the at least one pair of first engagement portions, the lens array being sandwiched between the second engagement portion and the pair of first engagement portions.
16. The lens unit according to claim 15 , wherein the at least one pair of first engagement portions is one of a plurality of pairs of first engagement portions and the at least one second engagement portion is one of a plurality of second engagement portions.
17. The lens unit according to claim 15 , wherein the lens array is injection molded.
18. A light emitting diode head incorporating the lens unit according to claim 15 .
19. An exposing unit incorporating the lens unit according to claim 15 .
20. An image forming apparatus incorporating the lens unit according to claim 15 .
21. An image reading apparatus incorporating the lens array according to claim 15 .
22. The lens unit according to claim 15 , wherein the at least one second engagement portion is one of at least two second engagement portions,
wherein the shielding member has a recess formed between adjacent second engagement portions so that the at least two second engagement portions are spaced by the recess, and the recess defines a gap between the lens array and the shielding member.
23. The lens unit according to claim 15 , wherein the at least one pair of first engagement portions are in the shape of a hook and the at least one pair of third engagement portion are in the shape of a recess, and the lens array is held in abutting relation with the at least one second engagement portion.
24. The lens unit according to claim 15 , wherein the lens array is injection-molded.
25. A light emitting diode head incorporating the lens unit according to claim 15 .
26. An exposing unit incorporating the lens unit according to claim 15 .
27. An image forming apparatus incorporating the lens unit according to claim 15 .
28. A lens unit comprising:
a shielding member including diaphragms formed therein and aligned in a first direction, the shielding member including a first engagement portion;
a lens array including a plurality of lens elements aligned in a second direction substantially parallel to the first direction, the lens array including a second engagement portion for engaging the first engagement portion to correct deformation of the lens array,
wherein the lens array is injection molded and includes an impressed recess caused by an ejector pin of a mold part when the lens array is pushed out of the mold part by the ejector pin,
wherein the shielding member includes a third engagement portion located such that when the lens array is assembled to the shielding member, the third engagement portion is in a vicinity of the impressed recess.