Lens array unit, method of manufacturing lens array unit, and optical device using the lens array unit

• US 6,693,748 B1
• Filed: 09/27/2001
• Issued: 02/17/2004
• Est. Priority Date: 03/31/1999
• Status: Expired due to Term

• Current Assignee: ROHM Co., Ltd.
• Original Assignee: ROHM Co., Ltd.
• Inventors: Imamura, Norihiro, Fujimoto, Hisayoshi, Takakura, Toshihiko
• Primary Examiner(s): Epps, Georgia
• Assistant Examiner(s): Harrington, Alicia M.
• Application Number:
  US09/937,566
• Time in Patent Office: 873 Days
• Field of Search: 359/618, 359/619, 359/620, 359/621, 359/622, 359/623, 359/455, 359/459, 264/1.7, 264/2.5
• US Class Current: 359/621
• CPC Class Codes: G02B 3/0025 Machining, e.g. grinding, polishing, diamond turning, manufacturing of mould parts
• CPC Class Codes: G02B 3/0062 Stacked lens arrays, i.e. refractive surfaces arranged in at least two planes, without structurally separate optical elements in-between
• CPC Class Codes: G02B 3/0068 arranged in a single integral body or plate, e.g. laminates or hybrid structures with other optical elements G02B5/1885, G02B17/002, G02B30/27 take precedence
• CPC Class Codes: G02B 3/0075 characterized by non-optical structures, e.g. having integrated holding or alignment means
• CPC Class Codes: H04N 1/0311 using an array of elements to project the scanned image elements onto the photodetectors H04N1/0318 takes precedence

Abstract

A lens array unit (U1) comprises a first and a second lens arrays (1, 2). The first and the second lens arrays (1, 2) include respectively a plurality of lenses (11, 21), each serving as a convex lens, for formation of a non-inverted, non-magnified image. In each of the lens arrays, the lenses (11, 21) and supports (10, 20) which hold the lenses are formed integrally of a translucent resin. Therefore, manufacture of the lens array is easy.

Claims

1. A lens array unit comprising:

a first lens array including a plurality of first lenses each serving as a convex lens, and a first support holding the first lenses, the first lenses and the first support being formed integrally of a translucent resin;

a second lens array including a plurality of second lenses each serving as a convex lens, and a second support holding the second lenses, the second lenses and the second support being formed integrally of a translucent resin;

characterized that the first and the second lens arrays are placed, one on the other, with each of the first lenses in alignment with a corresponding one of the second lenses on a same axis, for formation of a non-inverted, non-magnified image.

2. The lens array unit according to claim 1, wherein the separating means is provided only in the first lens array.

3. The lens array unit according to claim 2, wherein the light shield is capable of absorbing light received.

4. The lens array unit according to claim 1, wherein the separating means includes a light shield isolating the first lenses from each other.

5. The lens array unit according to claim 4, wherein the light shield includes at least one recess provided in the first support for the isolation of the first lenses from each other.

6. The lens array unit according to claim 5, wherein the light shield further includes a dark material covering a surface which defines the recess.

7. The lens array unit according to claim 6,

wherein the first support includes a first surface, and a second surface away from the first surface at a distance in a direction of the axis'"'"'s of the first lenses and faced to the second lens array, and

wherein the recess is provided in at least one of the first and the second surfaces, without penetrating the first support.

8. The lens array unit according to claim 7, wherein the recess is provided in each of the first and the second surfaces.

9. The lens array unit according to claim 7, wherein the recess is provided only in one of the first and the second surfaces.

10. The lens array unit according to claim 7, wherein the separating means further includes a light shielding member covering the first surface of the first support.

11. The lens array unit according to claim 10, wherein the separating means further includes a light shielding member covering the second surface of the first support.

12. The lens array unit according to claim 4, wherein each of the first lenses has an outer circumferential surface rising from the first support, the light shield including a dark material covering the outer circumferential surface.

13. The lens array unit according to claim 1, wherein each plurality of the first and the second lenses are disposed in a straight row.

14. The lens array unit according to claim 1, wherein each plurality of the first and the second lenses are disposed in a plurality of rows having a narrow width and extending in a predetermined direction.

15. The lens array unit according to claim 14, wherein the separating means includes:

a first recess provided in the first support for separation of the first lenses from each other in the predetermined direction;

a second recess provided in the first support for separation of the first lenses from each other in a direction across the predetermined direction; and

a dark material covering surfaces which respectively define the first and the second recesses.

16. The lens array unit according to claim 15, wherein the first and the second recesses communicate with each other.

17. The lens array unit according to claim 15, wherein the first recess has a depth axially of the first lenses, deeper than a depth of the second recess.

18. The lens array unit according to claim 15, wherein the second support is provided with means for optical separation of the second lenses from each other only in the predetermined direction.

19. The lens array unit according to claim 1, wherein each plurality of the first and the second lenses are disposed in a matrix, for formation of an image having a predetermined area.

20. The lens array unit according to claim 19, wherein the separating means includes at least one recess surrounding each of the first lenses, and a dark material covering a surface which defines the recess.

21. The lens array unit according to claim 1, wherein one of the first and the second lens arrays is provided with a recess while the other of the first and the second lens arrays is provided with a projection corresponding in shape and position to the recess, the first and the second lens arrays being joined together by fitting the projection into the recess.

22. The lens array unit according to claim 1, wherein the first lenses have a longer axial length than the second lenses.

23. The lens array unit according to claim 1, wherein the second lenses have a larger diameter than the first lenses.

24. The lens array unit according to claim 23,

wherein each of the first lenses includes a first lens surface and a second lens surface away from the first lens surface, and each of the second lenses includes a third lens surface closely facing the second lens surface and a fourth lens surface away from the third lens surface;

wherein the second lens surface has a larger diameter than the first lens surface;

wherein the third lens surface has a diameter equal to or larger than that of the second lens surface; and

wherein the fourth lens surface has a larger diameter than the third lens surface.

25. The lens array unit according to claim 23, wherein the fourth lens surfaces are connected together.

26. The lens array unit according to claim 23, wherein the second lens array is provided with a recess isolating the fourth lens surfaces from each other.

27. A method of manufacturing a lens array, comprising:

a resin-component-block forming step of forming a resin component block of a translucent resin, the resin component block integrally including a plurality of rows of lenses and supports holding the lenses; and

a dividing step of dividing the resin component block into a plurality of lens arrays each including a row of the lenses.

28. The method according to claim 27, wherein the resin component block has an outer edge surrounding a region formed with the lenses, the outer edge having at least a portion thicker than the region formed with the lenses.

29. The method according to claim 27, further comprising a light shield forming step of providing a light shield isolating the lenses from each other.

30. The method according to claim 29, wherein the light shield forming step includes a step of providing a recess isolating the lenses from each other in the resin component block, and a coating step of coating a surface which defines the recess, with a dark material.

31. The method according to claim 30, wherein the recess is formed in the resin-body forming step.

32. The method according to claim 30, wherein the recess is formed by a mechanical machining performed to the resin body.

33. The method according to claim 30, wherein the recess is formed by a laser machining performed to the resin body.

34. The method according to claim 30, wherein the coating step includes:

a step of applying a dark paint to the surface of the resin body which defines the recess and a lens surface adjacent to the recess, of each lens; and

a step of removing the paint from the lens surface before the paint applied to the lens surface dries and hardens.

35. The method according to claim 34, wherein each lens has an outer circumferential surface rising from the first support.

36. An optical device comprising image forming means which forms an image of an object at a predetermined place by focusing light from the object, characterized

that the image forming means is provided by a lens array unit, and

that the lens array unit comprises:

a first lens array unit including a plurality of first lenses each serving as a convex lens, and a first support holding the first lenses, the first lenses and the first support being formed integrally of a translucent resin;

a second lens array unit including a plurality of second lenses each serving as a convex lens, and a second support holding the second lenses, the second lenses and the second support being formed integrally of a translucent resin; and

that the first and the second lens arrays are placed, one on the other, with each of the first lenses in alignment with a corresponding one of the second lenses on a same axis, for formation of a non-inverted, non-magnified image.

37. The device according to claim 36, further comprising a transparent plate capable of guiding the document, the transparent plate being formed integrally with the divergent lens.

38. The device according to claim 36, further comprising a divergent lens disposed between the lens array unit and the light receiving elements for divergence of light having passed the lenses of the lens array in a direction across the predetermined direction.

39. The device according to claim 36, comprising:

at least one image display disposed in front of the lens array unit;

a translucent screen disposed behind the lens array unit; and

an auxiliary lens disposed between the screen and the lens array unit;

wherein an image displayed in the image display is enlarged or reduced into a non-inverted image on the screen by the lens array unit and the auxiliary lens.

40. The device according to claim 39, comprising a plurality of the image displays, the auxiliary lens being provided by a divergent lens, images displayed in the respective image displays being enlarged into an integrated non-inverted image on the screen.

41. The device according to claim 39, wherein the screen is provided by a color filter including a filter element for each color of red, green and blue.

42. The device according to claim 39, wherein a screen surface away from the auxiliary lens is convex or concave.

43. An optical device comprising image forming means which forms an image of an object at a predetermined place by focusing light from the object,

wherein the image forming means is provided by a lens array unit which comprises:

a first lens array unit including a plurality of first lenses each serving as a convex lens, and a first support holding the first lenses, the first lenses and the first support being formed integrally of a translucent resin; and

a second lens array unit including a plurality of second lenses each serving as a convex lens, and a second support holding the second lenses, the second lenses and the second support being formed integrally of a translucent resin;

the first and the second lens arrays being placed, one on the other, with each of the first lenses in alignment with a corresponding one of the second lenses on a same axis, for formation of a non-inverted, non-magnified image;

wherein the optical device further comprises;

at least one image display disposed in front of the lens array unit;

a translucent screen disposed behind the lens array unit; and

an auxiliary lens disposed between the screen and the lens array unit; and

wherein an image displayed in the image display is enlarged or reduced into a non-inverted image on the screen by the lens array unit and the auxiliary lens.