Substrate with recess portion for microlens, microlens substrate, transmissive screen, rear type projector, and method of manufacturing substrate with recess portion for microlens

• US 20050128595A1
• Filed: 12/15/2004
• Published: 06/16/2005
• Est. Priority Date: 12/16/2003
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Shimizu, Nobuo
• Granted Patent: US 7,319,242 B2
• Time in Patent Office: Days
• US Class Current: 349/98
• CPC Class Codes: G02B 3/0031 Replication or moulding, e.g. hot embossing, UV-casting, injection moulding
• CPC Class Codes: G02B 3/0056 arranged along two different directions in a plane, e.g. honeycomb arrangement of lenses G02B3/0043 takes precedence; miniaturised objectives for electronic devices employing wafer level optics G02B13/0085

Abstract

A microlens substrate is provided having a plurality of first microlenses and a plurality of second microlenses which are located between the plurality of first microlenses. The second microlenses are smaller than the first microlenses.

Claims

1. A substrate with a plurality of recess portions for forming microlenses, comprising:

a plurality of first recess portions; and

a plurality of second recess portions that are located between the plurality of first recess portions, the second recess portions being smaller than the first recess portions.

2. The substrate with the recess portions for the microlenses according to claim 1, wherein the plurality of first recess portions are arranged in substantially a grid shape.

3. The substrate with the recess portions for the microlenses according to claim 1, wherein the plurality of first recess portions are arranged in substantially a staggered shape.

4. The substrate with the recess portions for the microlenses according to claim 1, wherein a periphery of each first recess portion and a periphery of each second recess portion are located on a common planar surface of the substrate.

5. The substrate with the recess portions for the microlenses according to claim 1, wherein each of the first recess portions and the second recess portions is substantially circular.

6. The substrate with the recess portions for the microlenses according to claim 1, wherein the second recess portions are arranged to substantially eliminate a flat portion between the first recess portions.

7. The substrate with the recess portions for the microlenses according to claim 1, wherein a periphery of each first recess portion contacts a periphery of at least one of the second recess portions.

8. The substrate with the recess portions for the microlenses according to claim 1, further comprising third recess portions that are smaller than the second recess portions, wherein the third recess portions are located between the first recess portions in regions free from the second recess portions.

9. A microlens substrate manufactured using the substrate with the recess portions for the microlenses according to claim 1.

10. A microlens substrate in which a plurality of microlenses are formed on a substrate, comprising:

a plurality of first microlenses; and

a plurality of second microlenses that are located between the first microlenses, the second microlenses being smaller than the first microlenses.

11. A transmissive screen provided with the microlens substrate according to claim 10.

12. A rear type projector provided with the microlens substrate according to claim 10.

13. A method of manufacturing a substrate with a plurality of recess portions for forming microlenses, comprising:

a first recess portions formation step for forming a plurality of first recess portions in the substrate; and

a second recess portions formation step for forming a plurality of second recess portions in the substrate between the first recess portions, the second recess portions having a different size from the first recess portions.

14. The method of manufacturing a substrate with recesses portions for microlenses according to claim 13, wherein the second recess portions are smaller than the first recess portions.

15. The method of manufacturing a substrate with recess portions for microlenses according to claim 14, wherein after forming a plurality of openings in a mask formed on the substrate, the first recess portions and the second recess portions are formed on the substrate by etching the substrate.

16. The method of manufacturing a substrate with recess portions for microlenses according to claim 14, wherein after forming a mask on the substrate and forming a plurality of first openings in the mask, the first recess portions are formed in the substrate by etching the substrate, and then, after forming a new mask on the substrate and forming a plurality of second openings in the new mask, the second recess portions are formed in the substrate by etching the substrate.

17. The method of manufacturing a substrate with recess portions for microlenses according to claim 14, wherein after forming an etchable mask on the substrate to a predetermined thickness, and forming a plurality of first and second openings in the mask, the first recess portions and the second recess portions are formed in the substrate by etching the substrate.

18. A method of manufacturing a substrate with recess portions for forming microlenses, comprising:

forming a plurality of first openings in a first mask formed on the substrate;

forming a plurality of first recess portions in the substrate by carrying out a first etching process to the substrate through the first mask after the plurality of first openings are formed;

forming a plurality of second openings in a second mask formed on the substrate after the first etching processing is carried out, the second openings being located between positions where the first openings were located in the first mask; and

forming a plurality of second recess portions in the substrate by carrying out a second etching processing to the substrate through the second mask after the plurality of second openings are formed, the second recess portions having a size that differs from the first recess portions.

19. A method of manufacturing a substrate with recess portions for forming microlenses, comprising:

forming an etchable mask on the substrate while simultaneously forming a plurality of first and second openings in the mask, the mask being formed to a predetermined thickness and the second openings being formed between the first openings; and

forming two sets of recess portions in the substrate by carrying out an etching process to the substrate through the mask after the plurality of first and second openings are formed, the two sets of recess portions having different size recess portions.