Image display device with plural planar microlens arrays

• US 5,990,992 A
• Filed: 07/06/1998
• Issued: 11/23/1999
• Est. Priority Date: 03/18/1997
• Status: Expired due to Fees

• Current Assignee: Nippon Sheet Glass Company Limited
• Original Assignee: Nippon Sheet Glass Company Limited
• Inventors: Hamanaka, Kenjiro, Kishimoto, Takashi
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): CHOWDHURY, TARIFUR RASHID
• Application Number:
  US09/110,797
• Time in Patent Office: 505 Days
• Field of Search: 349/95, 349/158, 359/365, 359/366
• US Class Current: 349/95
• CPC Class Codes: G02B 3/0025 Machining, e.g. grinding, polishing, diamond turning, manufacturing of mould parts
• 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
• 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: G02F 1/133526 Lenses, e.g. microlenses or Fresnel lenses

Abstract

A reflective or transmissive image display device having a light-transmissive panel to which illuminating light for illuminating pixels is applied. The light-transmissive panel has laminated glass substrates having respective first and second planar microlens arrays. The glass substrates have their thicknesses adjusted by grinding to equalize focal lengths and other parameters of the first and second planar microlens arrays to preset values. Lenses of the first and second planar microlens arrays are formed by etching recesses in fire-finished surfaces of the glass substrates and filling the recesses with a synthetic resin having a high refractive index.

Claims

1. An image display device for controlling reflectivity with respect to illuminating light applied to pixels depending on an image to be displayed, comprising:

reflecting means for reflecting illuminating light toward a readout side thereof; and

a light-transmissive panel positioned on said readout side of said reflecting means, said light-transmissive panel comprising a first planar microlens array having lenses for converging the illuminating light and a second planar microlens array having lenses for refracting the illuminating light, which has passed through said first planar microlens array, so as to be applied substantially perpendicularly to said reflecting means, at least one of said first microlens array and said second microlens array further comprising a glass substrate wherein the lenses of said at least one of said first microlens array and said second microlens array are formed of a synthetic resin having high refractive index in a range of 1.58 to 1.63 to be convex lenses which project convexly away from said glass substrate, said convex lenses being covered by a cover glass with a layer of a synthetic resin of low refractive index in a range of 1.45 to 1.53 being formed between said convex lenses and said cover glass.

2. An image display device for controlling transmissivity with respect to illuminating light applied to pixels depending on an image to be displayed, comprising:

transmitting means for transmitting illuminating light from an illuminating side toward a readout side thereof;

a light-transmissive panel positioned on said illuminating side of said transmitting means, said light-transmissive panel comprising a first planar microlens array having lenses for converging the illuminating light and a second planar microlens array having lenses for refracting the illuminating light, which has passed through said first planar microlens array, so as to be applied substantially perpendicularly to said transmitting means, at least one of said first microlens array and said second microlens array further comprising a glass substrate wherein the lenses of said at least one of said first microlens array and said second microlens array are formed of a synthetic resin having high refractive index in a range of 1.58 to 1.63 to be convex lenses which project convexly away from said glass substrate, said convex lenses being covered by a cover glass with a layer of a synthetic resin of low refractive index in a range of 1.45 to 1.53 being formed between said convex lenses and said cover glass.