Title:
TRANSPARENT SHEET CONTAINING DIRECTIONAL IMAGE
Document Type and Number:
Japanese Patent JPS61261701
Kind Code:
A
Abstract:
This invention concerns a transparent sheet containing a directional image and method for forming such a sheet. A directional image is created in a transparent sheet comprising a monolayer of microlenses by forming deformations or axial markings in at least some of the microlenses by irradiation with a laser beam. The sheet may further comprise a partially light transmissive mirror disposed behind at least some of the microlenses. The directional images may be formed in transparent sheet which has been applied to a document as an overlay. When viewed under diffuse lighting conditions, the deformations appear as a dark image. The deformations may be formed so that when viewed under retroreflective conditions within a conical field the image is darker than the surrounding background, and when viewed under retroreflective conditions outside the conical field the image is brighter than the surrounding background.
Inventors:
PORTER GERALD R (US)
BRADSHAW THOMAS I (US)
HOCKERT ERIC N (US)
BRADSHAW THOMAS I (US)
HOCKERT ERIC N (US)
Application Number:
JP10839786A
Publication Date:
November 19, 1986
Filing Date:
May 12, 1986
Export Citation:
Assignee:
MINNESOTA MINING & MFG
International Classes:
G02B5/128; G02B5/12; G06K19/14; (IPC1-7): G02B5/128
Domestic Patent References:
| JPS5941162A | 1984-03-07 | |||
| JPS59148004A | 1984-08-24 |
Foreign References:
| US4200875A | 1980-04-29 |
Attorney, Agent or Firm:
Hideto Asamura
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