Microlens array, optical apparatus, single lens reflex camera and optical finder

• US 6,836,619 B2
• Filed: 06/17/2002
• Issued: 12/28/2004
• Est. Priority Date: 06/20/2001
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Ohmura, Yusuke
• Primary Examiner(s): Gray, David M.
• Application Number:
  US10/174,361
• Publication Number:
  US 20030002871A1
• Time in Patent Office: 925 Days
• Field of Search: 359/619, 359/626, 396/150, 396/382
• US Class Current: 396/150
• CPC Class Codes: G02B 5/0221 the surface having an irregular structure G02B5/0226 takes precedence
• CPC Class Codes: G02B 5/0278 used in transmission
• CPC Class Codes: G03B 13/24 Focusing screens

Abstract

In the microlens array, a plurality of microlenses are formed with an irregularity or probability-distributed regularity so as to differ from a hypothetical base pattern, the hypothetical base pattern having apexes of hypothetical microlenses each spaced apart from every adjacent microlens thereof by an equal distance L. All the apex positions of the microlenses lie within circles each centered on an apex position in said hypothetical base pattern and having a radius equal to or smaller than 0.3L, or meet a condition: 0.4L ≦P ≦1.6L. In this way, a microlens array with bright and clean viewing characteristics and a high reproducibility of a shape of each microlens is provided.

Claims

1. A microlens array, comprising:

a plurality of microlenses formed with a regularity so as to differ from a hypothetical base pattern, the hypothetical base pattern having apexes of hypothetical microlenses each spaced apart from every adjacent microlens thereof by an equal distance L,

wherein the apex positions of the microlens lie within circles each centered on an apex position in said hypothetical base pattern and having a radius equal to or smaller than 0.3L and the microlens has an average F number of approximately 2.8 to 5.6.

2. An optical apparatus, comprising:

the microlens array according to claim 1.

3. A single lens reflex camera, comprising:

a focusing screen constituted by a microlens array according to claim 1.

4. An optical finder, comprising:

a focusing screen constituted by a microlens array according to claim 1.

5. A microlens according to claim 1, wherein said plurality of microlenses are formed with a probability-distributed regularity in which the probability increases for the apex positions to exist in a region nearest to the apex position in said hypothetical base pattern.

6. A microlens according to claim 1, wherein said plurality of microlenses are formed with a probability-distributed regularity in which the probability increases for the apex positions to exist in a region farther from the apex position in said hypothetical base pattern.

7. A microlens array, comprising:

a plurality of microlenses formed with a regularity so as to differ from a hypothetical base pattern, the hypothetical base pattern having apexes of hypothetical microlenses each spaced apart from every adjacent microlens thereof by an equal distance L,

wherein an apex interval P between microlenses adjacent to each other meets the following condition;

8. An optical apparatus, comprising:

the microlens array according to claim 7.

9. A single lens reflex camera, comprising:

a focusing screen constituted by a microlens array according to claim 7.

10. An optical finder, comprising:

a focusing screen constituted by a microlens array according to claim 7.

11. A microlens according to claim 7, wherein said plurality of microlenses are formed with a probability-distributed regularity in which the probability increases for the apex positions to exist in a region nearest to the apex position in said hypothetical base pattern.

12. A microlens according to claim 7, wherein said plurality of microlenses are formed with a probability-distributed regularity in which the probability increases for the apex positions to exist in a region farther from the apex position in said hypothetical base pattern.