Erecting life-size resin lens array and method of manufacturing it

• US 6,363,603 B1
• Filed: 08/25/1999
• Issued: 04/02/2002
• Est. Priority Date: 12/26/1997
• Status: Expired due to Fees

• Current Assignee: Nippon Sheet Glass Company Limited
• Original Assignee: Nippon Sheet Glass Company Limited
• Inventors: Hamanaka, Kenjiro, Kishimoto, Takashi, Nemoto, Hiroyuki
• Primary Examiner(s): Bryant, David P.
• Assistant Examiner(s): JIMENEZ, MARC QUEMUEL
• Application Number:
  US09/380,042
• Time in Patent Office: 951 Days
• Field of Search: 216/41, 216/471, 216/24, 216/26, 216/56, 216/87, 216/94, 216/97, 216/103, 216/104, 216/108, 216/49, 216/54, 216/8, 294/50, 249/114.1, 249/115, 249/117, 249/134, 249/83, 359/366, 359/365, 359/622, 359/619, 359/621, 359/819, 359/623, 430/320, 430/321, 430/312, 430/326, 205/79, 205/162, 205/163, 205/164, 205/80, 205/67, 205/70, 205/159, 205/183, 652/75, 653/56, 65/301.3, 156/643
• US Class Current: 29/458
• CPC Class Codes: B29C 33/20 Opening, closing or clamping
• CPC Class Codes: B29C 43/021 characterised by the shape of the surface
• CPC Class Codes: B29C 45/00 Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor injection blow-moulding B29C49/06
• CPC Class Codes: B29D 11/00278 Lenticular sheets B29D11/00269 takes precedence
• CPC Class Codes: B29L 2011/0016 Lenses
• CPC Class Codes: G02B 3/0012 characterised by the manufacturing method
• CPC Class Codes: G02B 3/0031 Replication or moulding, e.g. hot embossing, UV-casting, injection moulding
• 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: Y10T 29/4987 Elastic joining of parts
• CPC Class Codes: Y10T 29/49885 with coating before or during assembling
• CPC Class Codes: Y10T 29/49899 by multiple cooperating aligning means
• CPC Class Codes: Y10T 29/49982 Coating

Abstract

The present invention provides a method for manufacturing an erect image, unity magnification, resin lens array by injection molding. Two injection-molded lens plates are stacked such that convexly warped sides thereof face each other or such that a convexly warped side of the lens plate whose warp is greater than that of the other lens plate faces a concavely warped side of the other lens plate, while directions of resin injection thereof are aligned so as to optically avoid the influence of molding shrinkage. Engagement spigots and engagement sockets are employed in order to align the two lens plates. The two stacked lens plates are secured by clipping of peripheral portions thereof.

Claims

1. A method for manufacturing an erect image, unity magnification, resin lens array, comprising the steps of:

providing two lens plates which are each manufactured by injection molding using a single mold, both lens plates having a convexly warped side and a concavely warped side with hemispherical lenslets formed on both said sides and having clipping portions provided at peripheral edges thereof, one lens plate having at least two engagement spigots for alignment use provided in a region other than that where the hemispherical lenslets are formed on one facing side thereof, and the other lens plate having at least two engagement sockets for alignment use provided in the region on one facing side thereof, and

stacking the two lens plates which are convexly warped, such that the convexly warped sides thereof face each other or such that the convexly warped side of the lens plate whose warp is greater than that of the other lens plate faces the concavely warped side of the other lens plate, in order to correct a warp of each lens plate and assemble the erect image, unity magnification, resin lens array which is free of image distortion.

2. A method for manufacturing an erect image, unity magnification, resin lens array according to claim 1, further comprising a step of stacking two lens plates, which are convexly warped and involve molding shrinkage distributed substantially symmetrically with respect to a direction of resin injection in the injection molding, such that directions of resin injection thereof are aligned so as to optically avoid the influence of the molding shrinkage.

3. A method for manufacturing an erect image, unity magnification, resin lens array according to claim 2, further comprising a step of interposing a colored spacer between the two lens plates, the colored spacer having openings formed therein in a regularly arrayed pattern so as to correspond to the hemispherical lenslets.

4. A method for manufacturing an erect image, unity magnification, resin lens array according to claim 3, wherein the colored spacer is made of a material whose coefficient α

2 of thermal expansion meets the following expression;

5. A method for manufacturing an erect image, unity magnification, resin lens array according to any of claims 1, 2, 3 and 4, wherein the apexes of facing hemispherical lenslets of the two lens plates are brought into contact with each other, or a constant distance is established between the apexes of facing hemispherical lenslets of the two lens plates.

6. A method for manufacturing an erect image, unity magnification, resin lens array according to any of claims 1, 2, 3 and 4, wherein the two lens plates are stacked such that optical axes of hemispherical lenslets of the two lens plates are aligned in a direction perpendicular to a plane of the lens plate.

7. A method for manufacturing an erect image, unity magnification, resin lens array according to any of claims 1, 2, 3 and 4, wherein the two lens plates are stacked such that optical axes of hemispherical lenslets of the two lens plates are aligned in an inclined direction in relation to a plane of the lens plate.

8. A method for manufacturing an erect image, unity magnification, resin lens array according to any of claims 1, 2, 3 and 4, wherein the two lens plates are stacked by engaging the engagement sockets of one lens plate with the corresponding engagement of spigots of the other lens plate to thereby align the two lens plates.

9. A method for manufacturing an erect image, unity magnification, resin lens array according to any of claims 1, 2, 3 and 4, wherein the diameter of the engagement socket and the diameter of the engagement spigot are selected such that, when the socket and the spigot are engaged, a clearance is left therebetween, thus performing rough alignment, followed by fine alignment.

10. A method for manufacturing an erect image, unity magnification, resin lens array according to claim 8, wherein the two stacked, aligned lens plates are secured by fitting clips to the corresponding clipping portions provided at the peripheral edges thereof.

11. A method for manufacturing an erect image, unity magnification, resin lens array according to claim 9, wherein the two stacked, aligned lens plates are secured by fitting clips to the corresponding clipping portions provided at the peripheral edges thereof.

12. A method for manufacturing an erect image, unity magnification, resin lens array according to claim 10, wherein the two lens plates are bonded by an adhesive in the region other than that where the hemispherical lenslets are formed.

13. A method for manufacturing an erect image, unity magnification, resin lens array according to claim 11, wherein the two lens plates are bonded by an adhesive in the region other than that where the hemispherical lenslets are formed.